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Showing papers on "Testosterone published in 1978"


Journal ArticleDOI
TL;DR: To elucidate further pituitary influence on testicular function, the effect of PRL, GH, and LH alone or in various combinations on the maintenance of testicular LH receptor concentration and testosterone synthesis in response to LH (testicular responsiveness) in hypophysectomized adult rats is studied.
Abstract: To elucidate further pituitary influence on testicular function, we studied the effect of PRL, GH, and LH alone or in various combinations on the maintenance of testicular LH receptor concentration and testosterone synthesis in response to LH (testicular responsiveness) in hypophysectomized adult rats. Hypophysectomy reduced LH receptor concentration by 80% and testicular responsiveness to LH by 70% 7 days after surgery. Treatment with PRL (75 or 150 μg/day) or with GH (75 or 150 μg/day) initiated within 6 h after surgery and continued twice daily for 6 days partially prevented the loss of LH receptors. The effect of PRL (150 μg/day) plus GH (150 μg/day) on LH receptor concentration was additive. The combination of LH (5 μg/day), PRL, and GH prevented any loss of LH receptors after hypophysectomy. A positive effect of LH on its receptor occurred in the presence of PRL. Treatment of hypophysectomized rats with 5 /μg LH plus 150 /μg PRL enhanced the effect observed with PRL alone (1.31 pmol/testis vs. 1.68 ...

235 citations


Journal ArticleDOI
TL;DR: It is demonstrated that the early development of testicular FSH receptors in followed by a prominent rise in plasma FSH, with concomitant increases in testicular growth and LH receptor concentration, is an important factor in sexual maturation in the male rat.
Abstract: The relationships between plasma gonadotropins, testicular gonadotropin receptors, and plasma testosterone were examined during neonatal life and throughout sexual maturation in the rat The binding affinity of testicular LH receptors (24 X 10(10) M-1) was significantly higher than that of FSH receptors (21 X 10(9) M-1) at all stages of development The concentration of FSH receptors in the testis reached a peak between 10-15 days of age, then fell to a constant level from 25-90 days However, the testis content of FSH receptors increased continually with age and reached a plateau at day 60 Plasma FSH declined after birth to a nadir at 15 days, then rose rapidly to a peak at day 38, and fell to a plateau from day 50 through adult life In contrast to the rapidly changing profile of plasma FSH during early maturation, alterations in plasma LH were less marked throughout development Although a progressive rise in plasma LH concentration was observed between days 36-51, the simultaneous changes in testicular LH receptors and plasma testosterone were much more prominent Testicular LH receptors showed a continuous increase in concentration and total number with advancing age and testis growth The major rise in LH receptor concentration occurred between 15-38 days age, at the same time as the rise in plasma FSH concentration and the phase of rapid testicular growth Plasma testosterone fell during the 8th-24th days after birth, then rose rapidly between days 35-55 The pubertal rise in plasma testosterone occurred about 15 days after testicular LH receptors began to increase and was coincident with the continuing rise in LH receptor content from day 35 until day 55 and with the progressive increase in plasma LH during this period These observations have demonstrated that the early development of testicular FSH receptors in followed by a prominent rise in plasma FSH, with concomitant increases in testicular growth and LH receptor concentration The resulting increase in gonadal sensitivity to LH could be responsible for the marked increase in secretion of testosterone which occurs during puberty in the presence of a relatively small change in the circulating LH concentration The sequence of changes observed in gonadotropins and their testicular receptors is consistent with the view that FSH-induced testicular sensitivity to LH is an important factor in sexual maturation in the male rat

222 citations


Journal ArticleDOI
TL;DR: Results indicate that changes in the release of PRL (and possibly also GH) may plan an important role in mediating the effects of the photoperiod on testicular function in the golden hamster.
Abstract: In adult male hamsters, 2 months of exposure to a short photoperiod (5 h of light: 19 h of darkness) caused testicular regression and a precipitous decline in plasma PRL, in agreement with earlier reports from other laboratories. Depressed release of PRL cannot be explained by a reduction in testicular steroidogenesis, because castration of males kept in a long photoperiod did not reduce PRL levels and administration of testosterone to males kept in a short photoperiod failed to reverse the decline in plasma PRL concentration. Treatment of such “regressed” animals with PRL, GH, or ectopic pituitary transplants stimulated growth of the testes and the accessory reproductive glands, increased the concentration of LH receptors in the testes, and elevated plasma testosterone levels. A single injection of 250 μg PRL was sufficient to increase testicular LH binding, and chronic treatment with pituitary grafts completely reversed testicular regression. The effectiveness of exogenous PRL in stimulating testicular ...

205 citations


Journal ArticleDOI
TL;DR: The block in steroid biosynthesis caused by intravenous injection of human chorionic gonadotropin (hCG) was beyond pregnenolone synthesis, and was not dependent on impairment of cyclic AMP formation and availability.

196 citations


Journal ArticleDOI
TL;DR: Clinical, laboratory and radiological findings were evaluated in twenty‐nine men who had raised serum prolactin concentrations and pituitary tumours and found thatSuprasellar extension was detected in twenty of the twenty‐six men whoHad lumbar airencephalography.
Abstract: Clinical, laboratory and radiological findings were evaluated in twenty-nine men who had raised serum prolactin concentrations and pituitary tumours. Twenty-one had functionless pituitary tumours ('prolactinomas') and eight had acromegaly. Supraseller extension was detected in twenty of the twenty-six men who had lumbar airencephalography. Three patients were studied before, sixteen before and after and ten only after pituitary ablative therapy. Seventeen of these men complained of complete lack of libido and impotence and six had impaired libido and sexual potency; only six patients in this series denied reproductive symptoms. Thirteen of the impotent subjects had small soft testes, ten reduced facial and body hair and three had marked gynaecomastia. No features of hypogonadism were noted in the six patients without reproductive symptoms and none of the patients had galactorrhoea. Serum prolactin concentrations were higher and serum testosterone concentrations lower in the impotent men compared with those with normal sexual potency. Serum LH and FSH (both basal and in response to LHRH) oestradiol and oestrone concentrations were not different between the two groups and, except in those with post-operative hypopituitarism, were within the normal range. Following successful lowering of prolactin concentrations by surgery or bromocripitine or both, serum testosterone rose and potency returned; by contrast failure to lower prolactin concentrations was associated with persistent impotence and hypogonadism. The endocrine profile of low serum testosterone concentrations with gonadotrophins which had not risen into the range usually seen in primary hypogonadism (together with the parallel increase of LH and testosterone in one patient studied sequentially during treatment which suppressed prolactin levels to normal), suggested that the impaired gonadal function was caused by a prolactin-mediated disturbance of hypothalamic-pituitary function.

184 citations


Journal ArticleDOI
TL;DR: The dramatic histological response to hormonal replacement confirms the importance of androgens in bone modeling and remodeling.
Abstract: Osteoporosis has been reported to complicate androgen deficiency in males. Accordingly, we have evaluated an osteoporotic hypogonadal male with bone histomorphometry before and after 6 months of testosterone replacement. Androgen therapy resulted in increases in relative osteoid volum, total osteoid surface, linear extent of bone formation, and bone mineralization. The dramatic histological response to hormonal replacement confirms the importance of androgens in bone modeling and remodeling.

162 citations


Journal ArticleDOI
TL;DR: El and to a lesser extent E2 as well as the El/A ratio were significantly correlated with degree of obesity or fat mass, suggesting a possible role of fat tissue in the aromatization of androgens and the existence of an additional precursor of plasma El.
Abstract: Plasma sex hormone concentrations (testosterone, (T), androstenedione (A), oestrone (E1) and oestradiol (E2) were measured in forty post-menopausal women more than 4 years post-normal menopause. Correlations between these and age, years post-menopause (YPM), degree of obesity and fat mass respectively were studied. T and A, as well as E1 and E2 were positively correlated (P less than 0.01), but no statistically significant correlation between A and E1 was observed. Sex hormone concentrations in this group of postmenopausal women (greater than 4YPM) did not show any variation as a function of age, with the possible exception of E2 which showed a tendency to decrease in the late post-menopause. E1 and to a lesser extent E2 as well as the E1/A ratio were significantly corelated with degree of obesity or fat mass, suggesting a possible role of fat tissue in the aromatization of androgens. Neither the T/A nor the E2/E1 ratios were correlated with fat mass, suggesting that the reduction of 17 oxo-group does not occur in fat tissue. The E1/A ratio was significantly higher than the reported conversion rate of A in E1. This might suggest the existence of an additional precursor of plasma E1.

154 citations


Journal ArticleDOI
TL;DR: It is suggested that independent masculinization of GTH, female sexual behavior and masculine sexual behavior patterns is produced by the action of T and/or E2 on separate neural areas, and that these neural areas may be susceptible to theaction of hormones at different times.

145 citations


Journal ArticleDOI
TL;DR: It is demonstrated that in the rat, as in primates, perinatal exposure to testicular androgens influences the development of patterns of play behavior.

144 citations


Journal ArticleDOI
TL;DR: It is suggested that differences in maze learning are more greatly influenced by brain sex than by subsequent gonadal hormone secretions during adulthood and are also due to the tendency of females to make more exploration-linked errors.

139 citations


Journal ArticleDOI
TL;DR: After oestrogen treatment, testosterone and androstenedione virtually disappeared, while reduced but significant concentrations of their metabolites remained in similar proportions to those observed in the untreated carcinomatous tissue.
Abstract: The levels of steroids in prostatic tissues were determined by radioimmunoassay after solvent extraction of a single (300--600 mg wet tissue) sample and chromatography of extracts on hydroxyalkoxypropyl Sephandex microcolumns. In normal adult prostates (n = 18) the concentrations of steroids (mean +/- S.E.M. ng/g wet tissue) were: testosterone, 0.25 +/- 0.04; androstenedione, 0.13 +/- 0.03; 5alpha-androstane-3,17-dione (5alpha-androstanedione), 1.31 +/- 0.30; 17beta-hydroxy-5alpha-androstan-3-one (5alpha-dihydrotestosterone, DHT), 1.22 +/- 0.14; 5alpha-androstane-3alpha, 17 beta-diol (3alpha-androstanediol), 4.32 +/- 0.49; androsterone, 4.15 +/- 1.07; progestrone, 0.39 +/- 0.07; 17alpha-hydroxyprogestrone, 0.42 +/- 0.06. Concentrations of of steroids tissues from outer-gland regions were within the ranges found in the periurethral regions. In the prostates of newborn boys, the concentrations of all steroids were high, including progesterone and 17alpha-hydroxyprogesterone. Apart from 3alpha-androstanediol, the levels of which tend to increase after this age, the concentrations of all steroids were lower in the infant and pubertal prostates, but most were re-established to a variable extend in the adult tissues. This was particularly evident with respect to 5alpha-androstanedione and androsterone, and it is suggested that these two androgens may have a functional role in the mature prostate. The concentrations of testosterone, androstenedione, 5alpha-androstanedione, progesterone and 17alpha-hydroxyprogesterone in tissue taken from ten patients with benign prostatic hypertrophy (BPH) were similar to those in normal adult adult tissue. The concentration of DHT was markedly raised (5.33 +/- 0.46 ng/g) and the level of 3alpha-androstanediol and androsterone were reduced (1.40 +/- 0.12 ng/g respectively) in adenomatous compared with normal tissue. The concentrations of various androgens displayed remarkable interelationships which characterize normal and BPH tissues. The concentrations of testosterone, androstenedione, DHT and 3alpha-androstanediol were particularly high in the untreated prostatic carcinomatous tissue sample investigated, whereas the concentrations of 5alpha-androstanedione and androsterone were very low. After oestrogen treatment, testosterone and androstenedione virtually disappeared, while reduced but significant concentrations of their metabolites remained in similar proportions to those observed in the untreated carcinomatous tissue. Under the conditions of therapy, oestrogens are suggested to influence the uptake of androgens.

Journal ArticleDOI
TL;DR: The cellular source and gonadotropic control of follicular 17β-estradiol secretion were investigated and thecal preparations secreted relatively low amounts of estradiol in the absence of exogenous testosterone and somewhat higher quantities in its presence.
Abstract: The cellular source and gonadotropic control of follicular 17β-estradiol secretion were investigated. Theca and granulosa isolated from proestrous follicles of immature rats treated with pregnant mare's serum gonadotropin were cultured separately for 3 days in the presence or absence of LH (0.1 μg/ml), FSH (0.1 μg/ml), and/or testosterone (5 × 10-7 M). Medium was collected and replaced at 3, 6, 12, 24, 48, and 72 h of culture and measured for estradiol by radioimmunoassay. Granulosa cell cultures secreted negligible quantities of estradiol in the absence of exogenous androgen precursor. Addition of testosterone to the culture medium greatly increased the production of estradiol by granulosa cells. Estradiol secretion was sustained throughout the 3-day culture period only if both testosterone and FSH were included in the culture medium. Thecal preparations secreted relatively low amounts of estradiol in the absence of exogenous testosterone and somewhat higher quantities in its presence. Gonadotropins had ...

Journal ArticleDOI
TL;DR: Under the experimental conditions used, all the tumors studied responded to the choriogonadotropin both in binding and in the resultant stimulation of steroidogenesis, which should qualify the M5480 Leydig cell tumor as a model system for further studies on the mechanism of action of gonadotropic substances, on hormone receptors, and on hormonally responsive tumors.
Abstract: Testicular tumors are generally characterized by a loss of responsiveness to gonadotropins. The M5480 Leydig cell tumor is unusual, if not unique, in that it responds to human choriogonadotropin and to lutropin via increased steroidogenesis. This report describes the identification of two variants of the original M5480 tumor that have altered steroid output both in the basal state and in response to human choriogonadotropin. One of the tumors produces mainly progesterone, which is stimulated by the choriogonadotropin; the other tumor produces about equal amounts of progesterone and testosterone, and the secretion of both is stimulated by the choriogonadotropin. The dissociation constant describing the interaction between Leydig tumor cells and 125I-labeled human choriogonadotropin is between 3 and 5×10-11 M. This agrees with values reported for normal Leydig cells, although the tumor cells appear to have fewer receptors. The differences noted in the two tumors and normal Leydig cells may have arisen from alterations in gene regulation, or in mutations, involving one or more enzymes in the pathway in which progesterone is converted to testosterone. Under the experimental conditions used, all the tumors studied (seven generations) responded to the choriogonadotropin both in binding and in the resultant stimulation of steroidogenesis. This property, together with the characteristic that a homogeneous cell population can be obtained without enzymatic treatment, should qualify the M5480 Leydig cell tumor(s) as a model system for further studies on the mechanism of action of gonadotropin, on hormone receptors, and on hormonally responsive tumors.

Journal ArticleDOI
TL;DR: Treatment of adult male rats with the potent LHRH agonists led to a marked reduction of testicular LH and prolactin receptor levels accompanied by decreased plasma testosterone levels and testis, seminal vesicle and prostate weight.
Abstract: Treatment of adult male rats with the potent LHRH agonists [D-Leu6, des-Gly-NH210]LHRH ethylamide or [D-Ala6. des-Gly-NH210]LHRH ethylamide led to a marked reduction of testicular LH and prolactin receptor levels accompanied by decreased plasma testosterone levels and testis, seminal vesicle and prostate weight. Maximal inhibitory effects were seen at a dose of 50 ng. After a single injection, maximal inhibitory effects were seen at 2–4 days with return toward normal levels at later time intervals. Similar results were obtained with LHRH itself although 5 μg was required for maximal effects. When the LHRH analog was administered twice a week at the 100 ng dose, degenerative signs appeared in the seminiferous tubules after one week while at four weeks, degenerative changes were so advanced that almost all germ cells had disappeared leaving only Sertoli cells.

Journal ArticleDOI
TL;DR: In this article, a histometric analysis of perfused testes from 25 men ranging from 18 to 87 years of age was conducted to investigate whether the aging human male experiences a gradual decline in testosterone production, a phenomenon that should be reflected in the Leydig cell population of the testis.
Abstract: Existing evidence suggests that the aging human male experiences a gradual decline in testosterone production, a phenomenon that should be reflected in the Leydig cell population of the testis. It has been proposed that Leydig cells diminish in number with increasing age, but conflicting claims characterize reports of this topic. We have reinvestigated this possibility by histometric analysis of perfused testes from 25 men ranging from 18 to 87 years of age. Average single Leydig cell volume (2,943 +/- 623 micrometer 3, X +/- S.D.) did not change significantly with increasing age (r = 0.24, P greater than 0.2), suggesting that surviving cells remain active. Total testis weight (43.5 +/- 13.9 g) also did not change with age (r = 0.04, P greater than 0.5). However, both total Leydig cell volume and the absolute number of Leydig cells per individual decreased significantly as functions of age (r = -0.71, P less than 0.002, and r = -0.61, P less than 0.005, respectively). Analysis of relationship between these two parameters indicates that the total volume of Leydig cell cytoplasm contained within the human testis is determined by the number of cells present. Our results show that a pair of young adult testes endowed with more than 700 million Leydig cells at 20 years of age may be expected to undergo an attrition rate of approximately 80 million cells per subsequent decade of life. Thus, Leydig cell attrition is an important correlate of declining androgen status in aging men.

Journal ArticleDOI
TL;DR: Findings are consistent with an effect on calcitonin production of normal male testosterone concentrations and concentrations of the sex steroids during pregnancy and whether a deficiency of the hormone plays a role in postmenopausal osteoporosis, which requires urgent investigation.

Journal ArticleDOI
TL;DR: Findings indicate a direct inhibitory effect of the analog on gonadotropin secretion in the absence of the gonads, and may explain some paradoxical antifertility effects observed with high doses of LH-RH analogs which exceed the physiologic dose range.

Journal ArticleDOI
TL;DR: Estrogen formation was undetectable in testes at all stages examined, but the time of appearance of the capacity to form estrogens in the fetal ovary is similar to the onset of the Capacity of the fetal testis to synthesize testosterone.
Abstract: The conversion of radiolabeled androgen to estrone and 17 beta-estradiol was assessed in tissues of human embryos that varied from phenotypically indifferent stages (1-3 cm crownrump length) to midgestation (15. 1-20 cm crownrump length). Significant rates of estrogen synthesis were demonstrated only in ovaries, liver, and brain. Estrogen synthesis was undetectable in gonads from 1-3 cm fetuses, but by the 3.1-5-cm stage it had reached an average rate of 1.9 pmol . h-1 . mg protein -1 in ovaries and remained at this level of activity through the latest stages examined. Estrogen formation was undetectable in testes at all stages examined, but the time of appearance of the capacity to form estrogens in the fetal ovary is similar to the onset of the capacity of the fetal testis to synthesize testosterone. The capacity of the fetal ovary to form estrogen develops before histological differentiation of the tissue.

Journal ArticleDOI
TL;DR: Daily treatment of FSH caused a marked increase in both basal and stimulated levels of testosterone production, and no significant change in testicular [125I]iodo-FSH-binding capacity was detected in any treatment group.
Abstract: The effects of estrogen upon testicular gonadotropin receptors and Leydig cell responses were studied. Immature hypophysectomized rats were treated for 7 days with 50 μg FSH, with or without diethylstilbestrol (DES). Daily injections of FSH induced a marked increase in testis weight; this weight increase was inhibited by concomitant DES treatment. FSH also induced an increase in testicular LH/hCG receptor content; the increase in [125I]iodo-hCG binding was not affected by daily injections of low doses (0.01 and 0.2 μg) of DES but was prevented by treatment with high doses (5 and 20 μg) of DES. In contrast, no significant change in testicular [125I]iodo-FSH-binding capacity was detected in any treatment group. Functional responses of the Leydig cells of hypophysectomized rats were studied by incubation of decapsulated testes with or without a saturating concentration of hCG. Daily treatment of FSH caused a marked increase in both basal and stimulated levels of testosterone production. In contrast, with or ...

Journal ArticleDOI
TL;DR: The testosterone response to hCG could be attenuated by preceding hCG administration with an injection of 17 beta-estradiol, and estrogen acts directly on the Leydig cell to effect changes in the activities of certain enzymes important for testosterone synthesis.
Abstract: Suppression of plasma testosterone levels from a mean of 760 ng/dl to a mean of 295 ng/dl could be induced in normal young adult men 24 h after a single injection of 2 mg aqueous 17β-estradiol. Maximum suppression to 123 ng/dl was noted 36 h after estradiol administration. Neither LH nor FSH levels were similarly affected. After administration of 5000 IU hCG to a similar group of subjects, daily blood samples were obtained for testosterone and estrogen. Maximum testosterone levelsof 2060 ng/dl (basal, 784 ng/dl) were seen 96 h after hCG administration. Maximum estrogen levels of 163 pg/ml (basal, 73 pg/ml) were seen 36 h after hCG administration. The testosterone response to hCG could be attenuated by preceding hCG administration with an injection of 17β-estradiol. These results can be explained by the concept of enzyme inhibition; estrogen acts directly on the Leydig cell to effect changes in the activities of certain enzymes important for testosterone synthesis. Whether endogenous estrogen production by...

Journal ArticleDOI
TL;DR: The review suggests that the regulation of testicular steroidogenesis depends on a complex of adenohypopyhseal hormones that FSH and PRL are both important components of this complex and that steroidogenesis regulation in the testis resembles steroidogenesis Regulation in the ovary.
Abstract: The action of pituitary hormones on testicular steroidogenesis is reviewed with particular focus on follicle stimulating hormone (FSH) and prolactin (PRL). Production of androgens by the testis depends on luteinizing hormone (LH) and the action of LH on the Leydig cells. There is evidence that FSH augments the action of LH on plasma testosterone (T) levels and on the growth of androgen-dependent male accessory reproductive glands. During sexual maturation FSH has a physiological role in increasing the responsiveness of the testes to LH stimulation. PRL augments the effect of endogenous or exogenous LH on testicular steriodogenesis. The effects of PRL seem to indicate direct action on the Leydig cells. PRL also seems to increase stores of cholesterol ester to provide a pool of precursors for steroidogenesis. PRL may be very important in sexual maturation. The review suggests that the regulation of testicular steroidogenesis depends on a complex of adenohypopyhseal hormones that FSH and PRL are both important components of this complex and that steroidogenesis regulation in the testis resembles steroidogenesis regulation in the ovary.

Journal ArticleDOI
TL;DR: The tamoxifen, 20 mg/day for 10 days, to normal males produced a moderate increase in luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone, and estradiol levels, comparable to the effect of 150 mg of clomiphene citrate (Clomid) as discussed by the authors.

Journal ArticleDOI
TL;DR: Data imply the involvement of the androgen receptor in the nuclear retetion of [3H]MPA, a progestin with both androgenic and synandrogenic activities that stimulated the growth of mouse prostate-seminal vesicle, kidney, and submaxillary gland in vivo.
Abstract: Progestins are known to mimic, potentiate, and/or antagonize the actions of androgens in various mammalian target tissues. Such androgenic, synandrogenic, and antiandrogenic responses to progestins were not detected in mice with defective androgen receptors (Tƒm/Y mice). The inference that the androgen receptor, rather than a progestin receptor, mediates these responses in normal animals was tested by in vivo and in vitro experiments in castrate mice and rats. 17a- Acetoxy-6a-methylprogesterone (MPA), a progestin with both androgenic and synandrogenic activities, stimulated the growth of mouse prostate-seminal vesicle, kidney, and submaxillary gland. The specific nuclear uptake of [nH]MPA or nH-labeled androgens by these organs in vivo was reduced more effectively by 5adihydrotestosterone than by MPA. Similar results were obtained in rats. In contrast, there was no evidence of nuclear uptake in Tm/Y mice. These data imply the involvement of the androgen receptor in the nuclear retetion of [3H]MPA. The hyp...

Journal ArticleDOI
TL;DR: The results suggest that estrogen formed by aromatization within the corpora lutea may play an important role in the regulation of luteal function during pregnancy in the rat.
Abstract: The pronounced aromatizing ability of the rat corpus luteum and the ability of estradiol to maintain luteal progesterone synthesis suggest that estrogen formed within the luteal cell might act locally to maintain luteal function. To examine this hypothesis, rats were treated with either estradiol (100 μg/day), high or low levels of testosterone via Silastic capsules (20 cm or 1 cm in length), or dihydrotestosterone (20- cm capsule) after hypophysectomy and hysterectomy on day 12 of pregnancy. Hypophysectomy and hysterectomy caused serum progesterone and androgen levels, estradiol concentrations in the corpora lutea, and the content of estradiol receptor in luteal cell nuclei to decrease significantly, and caused the cessation of luteal growth. The daily administration of 100 μg estradiol or of high levels of testosterone via the 20-cm Silastic capsule increased the estradiol concentration in the corpora lutea dramatically, maintained serum progesterone from day 12 through day 15 at concentrations similar ...

Journal ArticleDOI
TL;DR: Azoospermia was diagnosed in six factory workers who had been chronically exposed to 1,2-dibromo-3-chloropropane and selective atrophy of the germinal epithelium, intact Sertoli cells, and a normal appearance of a relatively increased number of Leydig cells were found.

Journal ArticleDOI
TL;DR: It is indicated that in this species, treatment with T stimulates both sexual behavior and secondary sex character development, whereas treatment with E alone is without effect centrally or peripherally.
Abstract: The androgen aromatization hypothesis was examined in the male lizard, Anolis carolinensis. After castration, sc silastic implants of testosterone (T) restored both challenge and courtship behavior, while dihydrotestosterone (DHT) or 17/?-estradiol (E) had no effect on male behaviors. Both T and DHT, but not E, stimulated hypertrophy and colloid production by the renal sex segment, a secondary sexual characteristic of male lizards. In two separate studies, castrates received DHT in combination with E. In each replicate, half of the castrates responded with increases in courtship be- havior after hormone treatment. Epithelial cell height of the sex segment of all DHT and E-treated castrates was comparable to T- or DHT-treated castrates, but colloid production was not stimulated. These experi- ments indicate that in this species, treatment with T stimulates both sexual behavior and secondary sex char- acter development, whereas treatment with E alone is without effect centrally or peripherally. (Endocrinology 103: 1814, 1978)

Journal Article
TL;DR: While renal transplantation may restore reproductive function in men with chronic renal failure maintenance hemodialysis has no effect, transplant patients showed a significant improvement in sexual activity, a return of testosterone to normal, and a significant fall in LH levels.
Abstract: A comparative study of the capacity of maintenance hemodialysis and renal transplantation to reverse the uremic damage to testicular function in 27 men with chronic renal failure was performed over a two year period. Despite two years of stable hemodialysis there was only minor improvement in sexual activity. Testosterone levels failed to improve and luteinising hormone (LH) levels remained high. Elevation of serum follicle stimulating hormone (FSH) together with severe spermatogenic damage persisted. Transplant patients showed a significant improvement in sexual activity, a return of testosterone to normal, and a significant fall in LH levels. Fertility, as assessed by sperm count, was improved in 50% of transplant patients. Thus while renal transplantation may restore reproductive function in men with chronic renal failure maintenance hemodialysis has no effect.

Journal ArticleDOI
TL;DR: Castration negates the sex difference in the hyperglycemic response to the multiple low-dose SZ injections and enhances the hyper glycemic response in Castrated or non-castrated females, and in castrated males.
Abstract: The hyperglycemic response to multiple low-dose SZ injections was measured in castrated and non-castrated male and female mice with or without testosterone treatment. On the 10th day of the experiment, control males had plasma glucose concentrations that were significantly higher than those of control females. Castration of males decreased the hyperglycemic response, while testosterone treatment restored it. The glucose concentrations in castrated females were significantly greater than control females, but not different from castrated males. Testosterone administration to castrated or noncastrated females increased the hyperglycemic response to that seen in control males and in testosterone-treated castrated males. Thus, castration negates the sex difference in the hyperglycemic response to the multiple low-dose SZ injections. Testosterone enhances the hyperglycemic response in castrated or non-castrated females, and in castrated males.

Journal ArticleDOI
TL;DR: These findings fail to provide evidence in support of the “inhibin” hypothesis and suggest that T replacement results in a rise in circulating LH and FSH concentrations approximating those observed when all steroid treatment was discontinued.
Abstract: Plasma levels of testosterone (T) and estradiol (E) were determined in intact adult male rhesus monkeys before bilateral castration. Beginning on the day of orchidectomy, the precastration diurnal patterns in plasma T concentrations were replicated quantitatively by the sc implantation of T-containing Silastic capsules and by sc injections of T in oil. Preoperative plasma E levels were replicated by the sc implantation of E-containing Silastic capsules. Replacement with T and E maintained serum LH and FSH concentrations within or below the preoperative control ranges. Replacement with T alone also maintained circulating gonadotropins at concentrations similar to those observed before castration. Withdrawal of T replacement, while maintaining plasma E at precastration levels, resulted in a rise in circulating LH and FSH to concentrations approximating those observed when all steroid treatment was discontinued. These findings fail to provide evidence in support of the “inhibin” hypothesis and suggest that t...

Journal ArticleDOI
TL;DR: The circulating titer of androgen required for reflex performance which resembled that of intact rats was considerably less than the normal mean blood level, as previously found for copulatory behavior.