Showing papers in "The Journal of Clinical Endocrinology and Metabolism in 1972"
TL;DR: Growth hormone was secreted during both awake and asleep periods but the number of secretory episodes was less than in adole...
Abstract: Spontaneous growth hormone secretion rates and secretory patterns were studied in a group of normal prepubertal children, adolescents and young and older adults by determining the concentration of growth hormone in plasma samples obtained at 20-min intervals over a 24-hr period. Prepubertal children secreted growth hormone only during sleep and not while awake and had a mean secretion rate of 91 μg/24 hr (range 54–122 μg/24 hr). Mean duration of secretion was 110 min/24 hr (range 60–180 min/24 hr). Adolescents secreted growth hormone during both awake and sleep periods and had a mean secretion rate of 690 μg/24 hr (range 391–1406 μg/24 hr). Mean duration of secretion was 226 min/24 hr (range 100–300 min/24 hr). Secretion rates in young adults (21–41 yr) averaged 385 μg/24 hr (range 215–769 μg/24 hr). Average duration of secretion was 133 min/24 hr (range 100–300 min/24 hr). Growth hormone was secreted during both awake and asleep periods but the number of secretory episodes was less than in adole...
634 citations
TL;DR: The validity of the method in general and specifically the lack of interference by TBG in serum has been demonstrated by 1) superimposability of T4 standard curves in buffer and T4-free human serum, 2) observation of expected values of...
Abstract: A rapid, specific, precise and reproducible radioimmunoassay (RIA) for measurement of thyroxine (T4) in unextracted human serum is described. The procedure compares the ability of standards and unknowns to compete with radioactive T4 for binding sites on a T4-binding antiserum produced in rabbits by immunization with human thyroglobulin (Tg). The assay is set up in the presence of 1) 150 μg of 8-anilino-1-naphthalene sulfonic acid (ANS) in all tubes, to mobilize T4 from its binding with thyroxine binding globulin (TBG), and 2) barbital buffer to inhibit binding of T4 to thyroxine binding prealbumin (TBPA). The standard curve of the assay is regularly linear from 0.3–10 ng, thereby allowing accurate measurement of 1.2–40 μg/100 ml of T4, in one attempt, using 25 μl of serum. The validity of the method in general and specifically the lack of interference by TBG in serum has been demonstrated by 1) superimposability of T4 standard curves in buffer and T4-free human serum, 2) observation of expected values of...
558 citations
TL;DR: It is concluded that prolactin in human beings is at least as responsive as growth hormone to release by stress in most situations; the two hormones ...
Abstract: Human plasma prolactin, measured by a homologous radioimmunoassay, has been found to rise significantly in a number of situations associated with stress. The greatest elevations, averaging approximately five-fold, were seen during major surgery with general anesthesia. Absolute levels of prolactin were higher at all times during surgery in women than in men. Smaller but significant elevations were found with gastroscopy, proctoscopy, and exercise. In all situations except exercise the prolactin rise was as high as, or higher than, that of growth hormone. Hypoglycemia induced by 0.2 U/kg of insulin produced significant prolactin elevations in all of seven normal women. Major elevations of prolactin, but not growth hormone, occurred in a minority of normal women following sexual intercourse; prolactin did not rise significantly in their male partners. It is concluded that prolactin in human beings is at least as responsive as growth hormone to release by stress in most situations; the two hormones ...
547 citations
TL;DR: It was observed that plasma testosterone levels and the apparent free plasma testosterone concentration remain within the same range from adolescence until the age of 50 yr, but that from the 6th decade on, the mean plasma levels decrease rather rapidly, with a wide range of individual values.
Abstract: The influence of aging on plasma testosterone levels and testosterone metabolism in males was studied. It was observed that plasma testosterone levels and the apparent free plasma testosterone concentration (AFTC) remain within the same range from adolescence until the age of 50 yr, but that from the 6th decade on, the mean plasma levels decrease rather rapidly, with however a wide range of individual values. As the metabolic clearance rate (MCR) decreases in male senescence, the net result is an important decrease in the testosterone blood production rate. Within the group of subjects studied, a statistically significant correlation between the free testosterone fraction and the MCR was found. It was observed that testosterone metabolism in male senescence is characterized by a relative decrease of the formation of androstanediols, with a relative increase of 5β over 5α metabolites;moreover a statistically significant correlation between the formation of 5α-androstane-3α,17β-diol and the free testosteron...
525 citations
TL;DR: Minute-to-minute fluctuations of serum LH and FSH concentrations resembling a pulsatile pattern were demonstrated in both pre- and post-menopausal women, and a greater net increase of circulating LH was found in pulses during the midcycle surge which was more than double that seen during other phases of the cycle.
Abstract: Minute-to-minute fluctuations of serum LH and FSH concentrations resembling a pulsatile pattern were demonstrated in both pre- and post-menopausal women A pulsatile pattern of LH but not FSH was seen during the menstrual cycle These appear to follow a varying frequency and magnitude according to the different phases of the cycle; a periodicity of 1–2 hr was seen during the early follicular phase, early luteal phase and midcycle surge while a periodicity of 4 hr was seen in the mid- and late-luteal phase During the late follicular phase only “minor oscillations” were noted A greater net increase of circulating LH was found in pulses during the midcycle surge which was more than double that seen during other phases of the cycle In contrast, post-menopausal subjects had pulses of both gonadotropins These were usually coincident, however, a minor asynchrony between LH and FSH patterns was discernible The frequency of pulses in the postmenopausal subjects was the same as in the follicular phase and midc
446 citations
TL;DR: A method is described for the enzymatic radioiodination of HCG, human follicle stimulating hormone (HFSH) and human luteinizing hormone (HLH) by a system consisting of lactoperoxidase, hydrogen peroxide and Na 125I, which is a gentle, simple and rapid method.
Abstract: A method is described for the enzymatic radioiodination of HCG, human follicle stimulating hormone (HFSH) and human luteinizing hormone (HLH) by a system consisting of lactoperoxidase, hydrogen peroxide and Na 125I. The hormones differed in their susceptibility to iodination. HCG was easily iodinated but HFSH and HLH required slightly higher concentrations of the enzyme and hydrogen peroxide. These hormones were labeled at specific activities satisfactory for radioimmunoassay. Biologic activities of these preparations were retained (HCG 108%, HFSH >62% and HLH 99%). Polyacrylamide gel electrophoresis (PAGE) of these tracers was consistent with their radiopurity. This lactoperoxidase catalyzed iodination is a gentle, simple and rapid method, and the radioiodinated preparations are suitable for radioimmunoassay.
422 citations
TL;DR: Synthetic thyrotropin releasing hormone (TRH) was administered intravenously to normal human subjects to define the normal range of serum TSH response to TRH and some of the variables that affect this response.
Abstract: Synthetic thyrotropin releasing hormone (TRH) was administered intravenously to normal human subjects to define the normal range of serum thyrotropin (TSH) response to TRH and some of the variables that affect this response. The maximum increase in serum TSH (maximum ΔTSH) following TRH was employed as the index of response. These were the results: 1) The maximum ΔTSH increased linearly when the TRH dose was increased from 6.25 to 400 μg. Since 800 μg produced no greater response than 400 μg, 400 μg is recommended as the standard test dose for evaluating TSH secretion. 2) Consistency of TSH response was evaluated by administration of the same dose (400 μg) of TRH to each of five subjects on four different occasions. The coefficients of variation of the maximum ΔTSH's in each subject ranged from 11–22% in four subjects and was 40% in the fifth. 3) TSH responsiveness to TRH was not significantly affected by sex. maximum ΔTSH in 20–39 year-old females was 16.8 ± 1.6 μU/ml (mean ± sem), and that in height- an...
385 citations
TL;DR: A rapid and simple method for the measurement of testosterone-estradiol-binding globulin in human plasma is described, and normal values were observed in abstinent alcoholics and in pregnant subjects with diabetes or hypertension.
Abstract: A rapid and simple method for the measurement of testosterone-estradiol-binding globulin in human plasma is described. The bind- ing protein is saturated with dihydrotestosterone (DHT), precipitated with 50% ammonium sul- fate, and the mass of bound DHT determined from the known specific activity of the added steroid. Normal values, expressed as M-g DHT bound/100 ml serum are: men, 0.93 ±. 0.06 (SEM); women, 1.85 ± 0.13; pregnancy, 12.4 ± 0.67. Elevated values were observed in men with cirrhosis of the liver and patients with thyrotoxi- cosis. Normal values were observed in abstinent alcoholics and in pregnant subjects with diabetes or hypertension. (/ Clin Endocrinol Metab 34: 983, 1972)
350 citations
TL;DR: The data suggest that in women, there is a relationship between the steroids 17-OHP and E2, and the mid-cycle peaks were observed in every normal cycle studied.
Abstract: Plasma levels of FSH, LH, progesterone (P), 17-hydroxy-progesterone (17-OHP), and estradiol-17β (E2) were measured daily by radioimmunoassay in eleven menstrual cycles from eleven normally menstruating women. The following criteria were used as indirect evidence for a normal ovulatory cycle: 1) mid-cycle LH peak, 2) luteal phase of 12–16 days duration, and 3) plasma progesterone above 5 ng/ml 5–8 days after the LH peak. Nine of eleven cycles studied were considered normal. A mid-cycle peak of E2 and 17-OHP was observed in every normal cycle studied. In one of the normal cycles, two peaks of plasma E2 occurred respectively on days 9 and 22. However, 17-OHP levels were low on day 9 and elevated on day 22. A gonadotropin surge occurred on day 22 followed by a normal luteal phase. The other two abnormal cycles studied either showed low levels of E2 and 17-OHP or a peak of only one of the two steroids. The data suggest that in women, there is a relationship between the steroids 17-OHP and E2, and the mid-cycle...
332 citations
TL;DR: Antibodies raised against cortisol-21-hemisuccinate conjugated to bovine serum albumin had a high affinity for cortisol, making this method particularly useful for measurement of 24-hr urine free cortisol.
Abstract: A radioligand assay for the measurement of cortisol in plasma and urine has been developed Antibodies raised against cortisol-21-hemisuccinate conjugated to bovine serum albumin had a high affinity for cortisol (K = 2 × 109 1/mole) A standard curve was established with a useful range from 010–40 ng Plasma cortisol is readily measured by directly assaying small aliquots of a methylene chloride extract of plasma Urine free cortisol was assayed after a single TLC of a methylene chloride extract of urine Intraassay variability of both urine and plasma cortisol determinations was 10%; interassay variability was 20–26% This method is particularly useful for measurement of 24-hr urine free cortisol
329 citations
TL;DR: The results indicate the presence of relatively specific binding sites for T3 in the nuclei of rat liver and kidney as well as other ultracentrifugal fractions.
Abstract: Injection of increasing quantities of L-triiodothyronine (T3) resulted in a progressive decrease in the proportion of T3 bound to the nuclear fraction of rat liver and kidney cells A similar dose-response relationship could not be demonstrated for other ultracentrifugal fractions Only a modest reduction in nuclear binding of thyroxine was observed after injection of large amounts of this iodothyronine The results indicate the presence of relatively specific binding sites for T3 in the nuclei of rat liver and kidney
TL;DR: The conversion of Δ4 to E1 in vitro by human female fat tissue was investigated and in patients with endometrial carcinoma an average conversion of 0.1% was found.
Abstract: The conversion of Δ4 to E1 in vitro by human female fat tissue was investigated. In patients with endometrial carcinoma an average conversion of 0.1% was found. The values ranged from 0.03 to 0.19%. In the other patients this conversion was only 0.027 % with a range of 0.01 to 0.06 %. The significance of these results is discussed.
TL;DR: The substrate specificity of the catechol-O-methyltransferase, purified from human liver 380-fold, has been tested with a variety of compounds, and under standard assay conditions, 2-hydroxy-17β-estradiol was the preferred substrate for the enzyme, as compared with epinephrine and other catechols tested.
Abstract: The substrate specificity of the catechol-O-methyltransferase, purified from human liver 380-fold, has been tested with a variety of compounds. Catechol estrogens, as well as catechol amines are methylated to their corresponding monomethyl ethers. The relation of the rates of methylation of catechol estrogens and catechol amines depended on enzyme and substrate concentration; under standard assay conditions, 2-hydroxy-17β-estradiol was the preferred substrate for the enzyme, as compared with epinephrine and other catechols tested. Km-values for 2-hydroxy-17β-estradiol were 15 μm, for 2-hydroxy-estrone 20 μm, for 2-hydroxy-estriol 25 μm and for-hydroxy-estrone 20 μm. For epinephrine and norepinephrine, Km-values of 300 μm and 200 μm, respectively, were obtained. The ratio of formation of the isomeric monomethyl ethers of catechol estrogens varied between 1.3 and 95, depending on the substrate incubated. On the basis of kinetic studies with different enzyme preparations, different inhibitors and different c...
TL;DR: This one-day method, using the disuccinate antibody and the LH-20 column, is associated with blank values difficult to distinguish from zero (< 6 pg).
Abstract: An accurate and relatively simple radioimmunoassay method for the measurement of aldosterone in human plasma is described. One ml or less plasma with 3H aldosterone (2 pg) is extracted with dichloromethane. Two alternative purification steps are described, either a standard paper chromatography (B5) or a more rapid Sephadex LH-20 column (60 × 1 cm) in the system dichloromethane: methanol 98:2 provides adequate purification for analysis. The assay uses either an antibody of high specificity generated against aldosterone-18, 21-disuccinate, or the 3-oxime coupled to bovine albumin. The samples, or standards, are incubated for 1–2 hours at 5° C with dilute antibody and 3H aldostercne. Separation of bound from free aldosterone is affected with activated and coarse-graded Florisil. This one-day method, using the disuccinate antibody and the LH-20 column, is associated with blank values difficult to distinguish from zero (< 6 pg). Aldosterone values from adrenalectomized subjects or duplicate samples after cort...
TL;DR: Results appear to indicate that specificity of TRH is not absolute in the functioning pituitary tumor secreting GH in patients with acromegaly or gigantism.
Abstract: Effect of TRH administration on serum TSH and GH was studied in 9 normal subjects and 11 patients with acromegaly or gigantism. TRH provoked a prompt increase of serum TSH in normal subjects, whereas no appreciable change of serum GH was observed. Serum TSH responses to TRH were lower in most of the patients, but 8 out of the patients showed a remarkable increase of serum GH within 30 min after TRH injection. These results appear to indicate that specificity of TRH is not absolute in the functioning pituitary tumor secreting GH.
TL;DR: LRF release, however, is minimal in prepubertal children and increases strikingly at puberty, and the magnitude of LH and possibly FSH release induced by LRF appears to be affected by the degree of prior exposure of LRF.
Abstract: The effect of puberty and hyper- and hypogonadotropism on the pituitary responsiveness to the intravenous injection of 5 μg/m2 to 600 μg of synthetic luteinizing hormone releasing factor (LRF) was studied in 32 subjects Sixteen subjects were prepubertal (2–13 years), 5 were pubertal (12–18 years), 6 were adult males, 3 had hypergonadotropic hypogonadism and 2 had hypogonadotropic hypogonadism and anosmia We conclude from our data that: 1) LRF releases comparable amounts of FSH in prepubertal, pubertal, and adult subjects LH release, however, is minimal in prepubertal children and increases strikingly at puberty; 2) LRF releases relatively more-LH and FSH in hypergonadotropic patients than in adult males; 3) LRF deficiency due to a selective hypothalamic defect is the origin of isolated FSH and LH deficiency in at least some patients with hypogonadotropic hypogonadism; and U) the magnitude of LH and possibly FSH release induced by LRF appears to be affected by the degree of prior exposure of th
TL;DR: The data indicate that the sensitivity of pituitary gonadotrophs to LRF is preferentially increased for LH release during the late follicular phase of the cycle and that a maximal pituitsary responsiveness to L RF appears to occur at the midcycle.
Abstract: Synthetic. LRF (IV 150 μg dose) elicited a prompt increase in circulating LH during all phases of the cycle studied. The maximal response was found during preovulatory phase and the minimal response was seen during the early follicular phase. A change in LRF responsiveness with greater and more sustained LH release from the early to the late follicular phase was observed. The response during luteal phase was significantly greater than responses in both the early and the late follicular phases. A concomitant but a much smaller response in the rise of serum FSH levels was observed. These data indicate that the sensitivity of pituitary gonadotrophs to LRF is preferentially increased for LH release during the late follicular phase of the cycle and that a maximal pituitary responsiveness to LRF appears to occur at the midcycle.
TL;DR: Data indicate that previous concepts that isolated defects of spermatogenesis exist in all such patients have been erroneous, particularly in the category of Sertoli-cell-only syndrome.
Abstract: The levels of plasma FSH, LH and testosterone were measured in 56 males who complained of infertility. Correlation between the hormonal results and seminal fluid sperm concentration was made. No apparent correlation existed between the various degrees of oligospermia and plasma FSH titers. Three conditions were invariably associated with elevated plasma FSH levels: (1) severe seminiferous tubular hyalinization, (2) azoospermia (excluding those patients with normal testicular histology) and (3) Sertoli-cell-only syndrome. Of interest was the observation that many of these patients additionally demonstrated abnormalities in the LH-testosterone axis. Careful attention was made to exclude patients with Klinefelter's syndrome in this consideration. These data indicate that previous concepts that isolated defects of spermatogenesis exist in all such patients have been erroneous, particularly in the category of Sertoli-cell-only syndrome. Cytogenetic studies identified chromosomal abnormalities in 11 of...
TL;DR: The response of plasma renin activity (PRA) to the stimuli of upright posture and sodium deprivation was determined in three normal adults and in ten hypertensive patients before and after chronic alpha-adrenergic receptor blockade with phenoxybenzamine and chronic beta-blockade with propranolol.
Abstract: The response of plasma renin activity (PRA) to the stimuli of upright posture and sodium deprivation was determined in three normal adults and in ten hypertensive patients before and after chronic alpha-adrenergic receptor blockade with phenoxybenzamine and chronic beta-blockade with propranolol. Alpha-receptor blockade produced little effect on supine or upright PRA values; beta-receptor blockade, however, consistently and significantly suppressed PRA in both the supine and standing positions. Dose-response studies suggest that the maximal suppression of PRA attainable after oral propranolol administration occurs at peak plasma levels of about 30–50 ng/ml. Beta-adrenergic receptors appear to constitute that part of the sympathetic nervous system which mediates a significant portion of the renin release mechanism. Pharmacologic interference with renin secretion by beta-adrenergic receptor blockade is easily achieved in both normal and hypertensive subjects. The suppression of supine and upright PRA with b...
TL;DR: This assay procedure, which avoids chromatography and uses only one organic solvent extraction had blank values which approached zero, and introduction of an additional thin layer chromatographic step was associated with ...
Abstract: A globulin fraction rich in bound testosterone was separated from serum by ammonium sulfate precipitation. Testosterone and related steroids were quantitatively extracted from this fraction with a benzene petroleum ether mixture and measured by radioimmunoassay using testosterone-3-tyrosine methyl ester-125I and a specific antiserum elicited against testosterone-3-oxime bovine serum albumin. This assay procedure, which avoids chromatography and uses only one organic solvent extraction had blank values which approached zero. The within and between assay error, measured as the coefficient of variation was 7.8% (n = 64) and 8.2% (n = 15), respectively. The minimum amount of hormone per sample which can be measured with good reliability is 0.17 ng. This provides sufficient hormone to account for losses during the procedure, and to allow quadruplicate samples for radioimmunoassay and an aliquot for determining recovery. Although introduction of an additional thin layer chromatographic step was associated with ...
TL;DR: An antibody obtained by immunizing a ewe with 11α-hydroxy-progesterone-hemisuccinate conjugated to bovine serum albumin was used for the assay of progesterone in crude plasma extracts and accuracy was confirmed by the recovery of known amounts of progestersone added to plasma.
Abstract: A specific progesterone antibody was obtained by immunizing a ewe with 11α-hydroxy-progesterone-hemisuccinate conjugated to bovine serum albumin. This antibody was used for the assay of progesterone in crude plasma extracts. The sensitivity of the assay was 0.05 ng. The accuracy was confirmed by the recovery of known amounts of progesterone added to plasma. The inter- and intra-assay coefficient of variation was 8%. Specificity was confirmed by a) checking cross reactivity of various steroids; b) failure of other steroids added to plasma to influence the accurate measurement of progesterone, and c) finding comparable progesterone levels in plasma extracts with and without chromatography. Mean values of progesterone (ng/ml) were 0.26 ± 0.08 (sd) in males and postmenopausal females; 0.50 ± 0.44 in preovulatory females; and 12.1 ± 4.81 in postovulatory females.
TL;DR: Serum FSH is normal, however, in most patients in whom spermatids and spermatozoa are detectable on testicular biopsy, and there is no relationship between the sperm count and the concentration of serum FSH.
Abstract: Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels, the sperm count and the histologic appearance of the testis were studied in 56 patients with azoospermia or oligospermia. FSH is elevated in those cases of azoospermia where gametogenesis is arrested prior to spermatid differentiation. Serum FSH is normal, however, in most patients in whom spermatids and spermatozoa are detectable on testicular biopsy. There is no relationship between the sperm count and the concentration of serum FSH. No correlation exists between serum LH and either the sperm count or the stage of spermatogenesis as evaluated on testicular biopsy.
TL;DR: In patients with galactorrhea and elevated serum prolactin values the ergot alkaloid effectively lowers serum Prolactin concentrations leading to a cessation of the galactor rhea.
Abstract: A single dose of 2 Bro-α-ergocryptine (CB-154) lowers serum prolactin for at least 12 hrs. in normal subjects. CB-154 in the immediate postpartum period causes a marked suppression of the elevated serum prolactin levels and completely inhibits puerperal lactation and breast engorgement. In patients with galactorrhea and elevated serum prolactin values the ergot alkaloid effectively lowers serum prolactin concentrations leading to a cessation of the galactorrhea.
TL;DR: The cell-free supernatant of the fragmented interstitial cell fraction was found to contain high affinity gonadotropin receptors, which showed rapid and specifically reversible binding of 125I-labeled LH and HCG.
Abstract: The specific binding of labeled gonadotropin to subcellular fractions of the rat testis has been utilized in the development of a sensitive radioligand assay system for LH and HCG. The cell-free supernatant of the fragmented interstitial cell fraction was found to contain high affinity gonadotropin receptors, which showed rapid and specifically reversible binding of 125I-labeled LH and HCG. For binding assays, satisfactory results were also obtained with the fraction prepared by centrifugation at 1500 g after homogenization of the whole testis. Assays were performed by incubation of tracer hormone with standards or samples and binding fraction for 2 hr at 37 C, or 16 hr at 24 C. Separation of bound and free tracer was performed by centrifugation and washing of the particulate receptor fraction, followed by measurement of the bound radioactivity. Parallel dose-response curves were obtained with human pituitary LH (LER 907), human urinary LH, and human chorionic gonadotropin, while ovine, bovine, and rat LH...
TL;DR: The presence or absence of a GH sleep-peak in the normals was not consistently related to the occurrence of slow-wave sleep, and none of the 6 acromegalics showed the usual GH peak early in sleep.
Abstract: Plasma growth hormone (GH) was measured during sleep in 12 normal volunteers of various ages and in 6 patients with acromegaly. Four of the 6 volunteers over 50 yr of age failed to show a sleep-peak of GH. The presence or absence of a GH sleep-peak in the normals was not consistently related to the occurrence of slow-wave sleep. None of the 6 acromegalics showed the usual GH peak early in sleep.
TL;DR: It is suggested that the initial hormonal event of female puberty is increased gonadotropin secretion, especially FSH, which rises sharply at the onset of puberty, but plate...
Abstract: The concentration of plasma estradiol (E2) was determined by radioimmunoassay in 26 prepubertal children, 76 pubertal females, 12 patients with idiopathic precocious puberty, six with premature thelarche, 8 with hypogonadism, and one with a feminizing ovarian tumor. Using 2.0 ml plasma aliquots, the sensitivity of the assay was 7 pg/ml. Pooled male (17 ± 0.71 pg/ml sem) and female (95 ± 6.9, pg/ml sem) plasma values agree with previous reports. Plasma E2, undetectable (< 7 pg/ml) in prepubertal children, rose steadily throughout puberty: P2 13 ± 2.4; P3 25 ± 4.5; P4 44 ± 12; and P5 (girls post-menarche) 58 ± 5.7. Plasma E2 correlated significantly with bone age (r = 0.52) and chronologic age (r = 0.54), but best with the clinical evaluation of sexual development (r = 0.59). Plasma E2 and plasma gonadotropin patterns inthis cross-sectional study suggest that the initial hormonal event of female puberty is increased gonadotropin secretion, especially FSH. FSH rises sharply at the onset of puberty, but plate...
TL;DR: The somatic manifestations of puberty in a cohort of 51 boys were correlated with changes in the concentrations of plasma testosterone, LH, and FSH, and a considerable variation in plasma hormone values was noted in P2 and P3.
Abstract: The somatic manifestations of puberty in a cohort of 51 boys were correlated with changes in the concentrations of plasma testosterone, LH, and FSH. The stage of pubertal development was graded (P1–P5), testicular size measured, and skeletal maturation determined. The mean concentration of plasma testosterone increased from 19 ng/100 ml ± 4.4 (sem) in P1, to 71 ng/100 ml ± 19 (sem) in P2, to 248 ng/100 ml ± 46 (sem) in P3, and to 482 ng/100 ml rfc 27 (sem) in P4–5. The mean concentration of plasma FSH (LER 869–2) rose from 0.8 ng/ml ± 0.05 (sem) in P1, to 0.96 ng/ml ± 0.15 (sem) in P2, to 1.7 ng/ml ± 0.3 (sem) in P3, to 2.5 ng/ml ± 0. 5 (sem) in P4–5. The mean concentration of plasma LH (LER 960) rose from 1.1 ng/ml ± 0.06 (sem) in PI, to 1.5 ng/ml ± 0.15 (sem) in P2, to 1.6 ng/ml ± 0.07 (sem) in P3, to 1.7 ng/ml ± 0.11 (sem) in P4–5. A considerable variation in plasma hormone values was noted in P2 and P3. The testicular volume index increased from 1.7 cm2 ± 0.1 (sem) in Pi, to 4.3 cm2 ± 0.6 (sem) in P2,...
TL;DR: The data indicate that significant maternal hyperparathyroidism regularity is occurring during all stages of pregnancy and in nonpregnant women of childbearing age.
Abstract: Parathyroid hormone (PTH) concentrations were measured by radioimmunoassay in sera from 75 women during all stages of pregnancy. In addition, PTH was determined in 14 women with well established lactation, and in 16 nonpregnant women of childbearing age. Serum PTH in the nonpregnant controls was 35 ± 4 (mean ± 1 se) with a range of 20–60. There was a significant decrease of serum PTH during the 20–24th weeks. Thereafter, a significant progressive rise occurred to a maximum value of 76 ± 5 (mean ± 1 se) during the 36–40th weeks. Seventeen of 20 women in their 9th month of pregnancy had values clearly above the normal range. In ten nonlactating women, 4–8 weeks postpartum, PTH was normal. In 14 women lactating 3 weeks to 27 months, PTH concentration was also normal. A slight decrease in total serum calcium concentration of 0.2 mg/100 ml was noted to occur between the 16th and 36th weeks, but this was not correlated with the rise in PTH. The data indicate that significant maternal hyperparathyroidism regular...
TL;DR: Plasma kinetics and metabolism of labeled dexamethasone were evaluated in nine subjects before and after administration of diphenylhydantoin and there were consistent decreases in t½'s and increases in metabolic clearance rate.
Abstract: Plasma kinetics and metabolism of labeled dexamethasone were evaluated in nine subjects before and after administration of diphenylhydantoin. Labeled dexamethasone was injected intravenously followed by frequent sampling of blood and urine. The labeled dexamethasone in plasma was isolated chromatographically. Total urine and fractional radioactivity after solvent extraction (chloroform and ethyl acetate), with and without glucuronide hydrolysis, were determined. Baseline plasma equilibrated t½'s and metabolic clearance rates (2 compartment model) ranged from 167 to 368 minutes and 222 to 456 liters/day, respectively. After diphenylhydantoin there were consistent decreases in t½'s and increases in metabolic clearance rate; mean changes —51% and +140% respectively. Mean recovery of urinary radioactivity at 4 and 24 hours was 16 and 64 percent of dose respectively. The largest fraction was a more polar unconjugated one, 7 and 31 percent of dose at 4 and 24 hours. Following diphenylhydantoin there was a signi...
TL;DR: This study failed to show a 24-hr LH rhythm or relationship of LH secretory activity to the sleep-wake cycle, and the marked temporal variability of the LH system throughout the 24-hour period clearly indicates demon...
Abstract: Plasma luteinizing hormone (LH) was measured by radioimmunoassay at 20-min intervals around the clock for 24 hr in 5 normal adult men. During the nocturnal S-hr sleep period, polygraphic monitoring of sleep stages was carried out. All 5 subjects showed episodic secretion of LH characterized by rapid rises and the declining slopes approximated the half-life of LH. Calculation of LH “half-life” from the declining phase of the LH secretory episodes gave variable estimates within subjects and between subjects (65–114 min). The longer T1/2 estimates calculated by this method, contrasted with previous studies where LH half-life was determined directly by the measurement of LH disappearance, is probably the result of small amounts of LH being secreted during the declining phase of the LH secretory episode. This study failed to show a 24-hr LH rhythm or relationship of LH secretory activity to the sleep-wake cycle. The marked temporal variability of the LH system throughout the 24-hr period clearly demon...