Showing papers on "Hypophysectomy published in 1973"
TL;DR: It has been demonstrated that in the rat, spermatozoa become able to fertilize ova when they reach the proximal region of the cauda epididymidis and lose this ability 3 days after castration and 4 days after hypophysectomy.
Abstract: It has been demonstrated that in the rat, spermatozoa become able to fertilize ova when they reach the proximal region of the cauda epididymidis Epididymal spermatozoa lose this ability 3 days after castration and 4 days after hypophysectomy Ligation of the ductuli efferentes or sham hypophysectomy has no effect Testosterone propionate (2 mg/kg/day) prevents the effect of castration or hypophysectomy Cyproterone acetate (20 mg/kg/day) successfully inhibits the effect of exogenous testosterone (2 mg/ kg/day) Spermatozoa from the distal cauda epididymidis lose their fertilizing ability within 4 days after castration (9%) and 6 days after hypophysectomy (13%) Testosterone propionate (2 mg/kg/day) maintains the fertilizing ability of the spermatozoa from the distal cauda Procedures (castration or hypophysectomy) which cause a decline in circulating androgen levels, hasten sperm transit through the epididymis Castration interferes with the acquisition by the spermatozoa of their mature progressive patt
184 citations
TL;DR: It is concluded that prolactin and LH are both necessary for the maintenance of the ovine CL, and that these two hormones together make up the `luteotrophic complex', which is similar to that seen in hysterectomized animals before hypophysectomy.
Abstract: The functional activity of ovine CL was assessed by their weight, DNA and RNA content, and the concentration of progesterone in ovarian venous blood. If sheep were hysterectomized on Days 9 to 12 of the oestrous cycle, the CL were maintained in a fully functional state until at least Day 60, but their activity had begun to decline by Day 128 to 135. When hysterectomized sheep were hypophysectomized, there was a significant decline in luteal activity within 48 hr, regardless of whether or not the pituitary stalk and pars tuberalis were left intact. The CL had almost completely stopped secreting progesterone within 4 days of hypophysectomy. Hysterectomized, hypophysectomized animals were therefore used in a series of experiments to test the luteotrophic properties of sheep pituitary gonadotrophins. Doses of up to 5 mg FSH/day were unable to prevent complete luteal regression; similarly, doses of up to 5 mg LH/ day were also without effect. When mixtures of FSH and LH were given, the results were no better. However, prolactin in doses of up to 1000 i.u./ day was invariably able to maintain functional CL for 12 days, although at a considerably reduced level of activity. When prolactin was combined with a small dose of LH (0\m=.\25mg/day), the CL were maintained at a level of activity comparable to that seen in hysterectomized animals before hypophysectomy. The slight synergistic action of FSH with prolactin was probably due to LH contamination. No further beneficial effects were obtained by adding FSH to the prolactin\p=m-\LHmixture. We conclude that prolactin and LH are both necessary for the maintenance of the ovine CL, and that these two hormones together make up the `luteotrophic complex'. But whilst prolactin on its own has
90 citations
TL;DR: The data suggested that the enhanced hepatic utilization of amino acids following hypophysectomy resulted from increased metabolism of the compounds in the liver, involving increased fluxes through the pathways of gluconeogenesis and ureogenesis.
84 citations
TL;DR: Hypophysectomy appears to be slightly more effective than adrenalectomy in advanced cancer of the prostate, especially in terms of short-term objective response, and has proved much more beneficial in breast cancer.
63 citations
TL;DR: Hormones which promote ageing changes or age-pathology are called “ageing hormones” and environmental influences such as stress, food supply and temperature also affect the course of ageing.
55 citations
TL;DR: The available evidence suggests that intact functioning adrenal glands are necessary for the normal circadian rhythm of β-hydroxy-β-methylglutaryl-CoA reductase to occur, but does not indicate which hormone or hormones are involved, nor does it indicate whether such hormone (or hormones) play a direct or a permissive role.
54 citations
TL;DR: It is suggested that either ACTH, prolactin or both may have hypercalcemic effects on fish in calcium-deficient environments.
50 citations
TL;DR: When ACTH and growth hormone were injected at the same time, a marked synergistic stimulation of ODA was observed, and a progressive fall in ODA responsiveness to a standard pulse of ACTH with increasing time after hypophysectomy was observed.
Abstract: The effects of ACTH and growth hormone on rat adrenal ornithine decarboxylase activity (ODA) were studied in hypophysectomized rats Administered independently, each hormone produced an increase in ODA as compared to saline—injected hypophysectomized controls ACTH caused a rise in ODA between 6 and 10 hr after stimulation with a peak at 8 hr Increasing doses of ACTH from 25 IU to 10 IU produced progressive increases in ODA The steroidogenic 1–24 portion of the ACTH molecule had full ODA—stimulating activity There was a progressive fall in ODA responsiveness to a standard pulse of ACTH with increasing time after hypophysectomy Growth hormone also produced a peak ODA response 8 hr after administration Progressively increasing ODA responses were obtained by increasing doses of growth hormone from 1 to 5 mg When ACTH and growth hormone were injected at the same time, a marked synergistic stimulation of ODA was observed (Endocrinology 92: 1089, 1973)
47 citations
TL;DR: It is put forward that in hypophysectomized rats, pentagastrin treatment stimulates pancreatic hyperplasia in addition to hypertrophy of the gland in the absence of the pituitary.
42 citations
TL;DR: Man aged 25 in 1968 History: Presented in 1968 with weight loss, hand tremor, sweating and heat intolerance, also infrequent shaving and minimal impairment of peripheral vision.
Abstract: Man aged 25 in 1968 History: Presented in 1968 with weight loss (20 kg in four years), hand tremor, sweating and heat intolerance. Also infrequent shaving and minimal impairment of peripheral vision. No family history of thyroid disorder. Appearance thin, with muscle wasting, hand tremor and onycholysis. Eyes normal. Smooth goitre (estimated weight 40-50 g) with bruit over both lobes: Pulse regular, rate 90/min. Scant hair growth in pubic, axillary and beard areas.
40 citations
TL;DR: Experimental verification of the crucial role of this endocrine axis in initiating parturition came from hypophysectomy or adrenalectomy of of foetal lambs, and studies extended the concept by showing that cortisol, dexamethasone and ACTH infusions could induce premature parturitions.
Abstract: Extract Prolonged gestation in cattle is characterized by abnormalities in the foetal pituitary and adrenal glands (Kennedy et al., 1967). Experimental verification of the crucial role of this endocrine axis in initiating parturition came from hypophysectomy or adrenalectomy of of foetal lambs (Liggins et al., 1967; Drost and Holm, 1968). Further studies extended the concept by showing that cortisol, dexamethasone and ACTH infusions could induce premature parturition in normal foetal lambs or induce parturition in hypophysectomized foetal lambs (Liggins, 1968).
TL;DR: It was concluded that growth hormone reestablished the second phase of insulin release by a mechanism different from that of ACTH or hy...
Abstract: The dynamics of glucose-induced insulin secretion, by pancreases from hypophysectomized rats, was studied by use of the isolated perfused pancreas. Although glucose-induced insulin release by these pancreases was found to be diphasic, the release pattern was quite different from the normal diphasic secretory pattern. The early phase of insulin release was extremely reduced (about a 70% depression), and the second secretory phase was also attenuated (about 30%). The first phase of release was fully depressed one week post hypophysectomy, but the second phase was not maximally depressed until later. Growth hormone treatment (daily, beginning 14 days prior to perfusion) of hypophysectomized rats reestablished the secondary release phase, but had no effect on the first phase. Conversely, either ACTH or hydrocortisone treatment successfully reestablished both phases of secretion. From these data it was concluded that growth hormone reestablished the second phase by a mechanism different from that of ACTH or hy...
TL;DR: The responsiveness of hypophysectomized rats to electric footshock (EFS) could not be altered by chronic treatment with adrenal maintenance doses of ACTH β1–24 and adrenalectomy appeared to be ineffective in modifying the responsiveness of rats to EFS.
TL;DR: The results indicate that growth hormone plays a role in the maintenance of adrenocortical secretion which is at least at least partially responsible for increased corticosterone output.
Abstract: Effects of growth hormone, alone or in combination with ACTH, on adrenal function in hypophysectomized rats were examined. Hypophysectomy reduced corticosterone secretion and increased adrenal 5α-reductase activity. Growth hormone, administered alone to hypophysectomized rats, lowered reductase activity without affecting corticosterone secretion. ACTH alone increased corticosterone output but only partially reversed the increment in reductase activity. As a result, ACTH-treated rats secreted large amounts of 5α-dihydrocorticosterone (DHB) and 3β-5α-tetrahydrocorticosterone (R), the principal adrenal metabolites of corticosterone. Growth hormone, when given with ACTH, potentiated the effects of ACTH by stimulating corticosterone secretion and lowering 5α-reductase activity further. The additional increment in corticosterone resulted in part from a decline in the secretion of DHB and R. These results indicate that growth hormone plays a role in the maintenance of adrenocortical secretion which is at least p...
TL;DR: The effect of hypophysectomy on the growth in length from the proximal growth plate of the tibia in female Sprague-Dawley rats was studied with the tetracycline method and the width of the fluorescent band indicated the functional efficacy of the hypophysektomy.
Abstract: The effect of hypophysectomy on the growth in length from the proximal growth plate of the tibia in female Sprague-Dawley rats was studied with the tetracycline method. The body weight was registered. The completeness of the hypophysectomy was determined microscopically on serial sections of the sella turcica. Hypophysectomy was found to have a retarding effect on longitudinal bone growth. In animals operated at 40 days of age the growth does not cease. The longitudinal growth decreases and reaches a low basal level about 10 days postoperatively. A single dose of 45 mg/kg cortisone acetate given at hypophysectomy has a growth retarding effect postoperatively. When hypophysectomy was performed at 30, 40, 50, or 60 days of age, young animals have a higher basal growth rate than older animals. The width of the fluorescent band, corresponding to a postoperative injection of oxytetracycline, is correlated to the growth rate and can be used as an index of the growth rate. The postoperative accumulated growth and the width of the fluorescent band indicate the functional efficacy of the hypophysectomy, and make it possible to separate animals with complete and incomplete hypophysectomy. Knowledge about the basal growth is important for the evaluation of the growth stimulating effect of different hormones.
TL;DR: The MOC in the rat was measured after ablation of the adrenals, gonads, pancreas, pineal, pituitary, thymus, thyroid and parathyroids, and various hormones were replaced alone or in certain combinations in intact or in operated rats.
Abstract: Minimal 02 consumption (MOC) in the rat was measured after ablation of the adrenals, gonads, pancreas, pineal, pituitary, thymus, thyroid and parathyroids. Only primary (thyroidectomy) or secondary (hypophysectomy) thyroid function ablation lowered the MOC. Various hormones were replaced alone or in certain combinations in intact or in operated rats: cortisone, corticosterone, desoxycorticosterone, estradiol, progesterone, testosterone, thyroxine (T4), triiodothyronine (T3), adrenocorticotrophic hormone (ACTH), growth hormone (GH), prolactin, vasopressin and oxytocin. Only T4, T3 increased the MOC. No hormone given with T4 altered the response to T4 given alone. GH doubled the body wt of young hypophysectomized rats but did not alter the MOC. (Endocrinology 93: 61, 1973)
TL;DR: Cells from the adrenals of hypophysectomized rats (up to 28 days after operation) require less adrenocorticotropic hormone to induce one-half maximal rate of production of 3',5'-adenosine monophosphate than do cells from the Adrenals of intact rats.
Abstract: Cells from the adrenals of hypophysectomized rats (up to 28 days after operation) require less adrenocorticotropic hormone to induce one-half maximal rate of production of 39,59-adenosine monophosphate than do cells from the adrenals of intact rats. A corresponding increase in sensitivity is reflected in the steroidogenic response to adrenocorticotropic hormone up to 2 days after hypophysectomy.
TL;DR: The data suggest that during prooestrus very high amounts of FSH are required to recruit a new crop of follicles, whereas during the other phases low levels of both FSH and/or I,H are a requirement for normal follicular growth.
Abstract: Rats were hypophysectomized at oestrus, at days i, 2 and 3 of dioestrus or at pro-oestrus. They were injected with various doses of PMS only, or of combinations of PMS and HCG, in such a way that rather constant blood levels could be expected. They were killed 24 hours later. It was found that the minimal doses of the substitutional gonadotrophins required to maintain normal follicular growth, were considerably higher during the period from prooestrus to oestrus (when a new generation of follicles starts its development) than during all other periods. This peak requirement primarily concerned PMS. The minimal requirement during other periods only showed minor variations. The data suggest that during prooestrus very high amounts of FSH are required to recruit a new crop of follicles, whereas during the other phases low levels of both FSH and/or I,H are a requirement for normal follicular growth.
TL;DR: The pituitary remnant was examined in patients in whom a stereotaxic, transsphenoidal, high-frequency coagulation had been performed because of widespread metastatic disease and it seems that the pituitaries can regenerate provided that the dominating hypothalamic centers remain undamaged during hypophysectomy.
Abstract: ✓ The pituitary remnant was examined in 13 patients in whom a stereotaxic, transsphenoidal, high-frequency coagulation had been performed because of widespread metastatic disease. The patients were divided in three groups according to the state of regeneration of pituitary tissue. The first group (patients dying 3 to 7 days after surgery) showed only signs of acute necrosis. The second group (patients dying 24 to 219 days after surgery) demonstrated mitotic figures and regenerated areas in the adenohypophysis. The third group (patients dying 252 to 353 days after surgery) showed no mitoses but large areas of regenerated glandular cells as a sign of completed regeneration. It seems that the pituitary can regenerate provided that the dominating hypothalamic centers remain undamaged during hypophysectomy.
TL;DR: The time of onset of hypothalamic regulation of the pituitary-adrenal system in fetal rats was assessed by induction of fetal exencephaly by maternal hypervitaminosis A and destruction of the fetal hypothalamic area with an electrocoagulator and the effects were compared with those of fetal hypophysectomy.
Abstract: The time of onset of hypothalamic regulation of the pituitary-adrenal system in fetal rats was assessed by induction of fetal exencephaly by maternal hypervitaminosis A and destruction of the fetal hypothalamic area with an electrocoagulator. The effects of such experiments were compared with those of fetal hypophysectomy (surgical decapitation). In fetuses decapitated and autopsied at various stages between the 17th and the 22nd day of gestation, the adrenals stopped growing from the day of decapitation. Brains of exencephalics at all stages from the 16th to 22nd days were everted and more or less degenerated, but pituitaries always persisted. The adrenals of such exencephalics grew nearly to thesame extent as did those of non-exencephalics until the 20th day after which they stopped growing despite the presence of the anterior pituitary. When hypothalamic destruction took place on day 17 of gestation, there was no alteration in adrenal growth during the subsequent day. Between the 18th and the 20th day,...
TL;DR: This chapter highlights the unique pituitary peptides with behavioral-affecting activity, which upon subcutaneous administration potently facilitate acquisition of conditioned avoidance responses in hypophysectomized rats and inhibit extinction ofavoidance responses in intact rats.
Abstract: Publisher Summary This chapter highlights the unique pituitary peptides with behavioral-affecting activity. Initial screening studies for behavioral-affecting activity were performed on hypophysectomized rats. Four unique porcine pituitary peptides are isolated and partially characterized, which upon subcutaneous administration potently facilitate acquisition of conditioned avoidance responses in hypophysectomized rats and inhibit extinction of avoidance responses in intact rats. The profound deficit in acquisition and retention of conditioned avoidance responses (CARS) imposed on rats by hypophysectomy can be substantially reversed by subcutaneous administration of corticotrophin (ACTH) and certain subunits thereof, as well as by the melanotrophins and pitressin. The potent behavioral effects of synthetic corticotrophin subunits in conjunction with an apparent lack of peripheral action suggested the possible existence of naturally occurring pituitary peptides with similar biological activity. The availability of a porcine pituitary extract in a large quantity afforded the opportunity to undertake a search for such compounds.
TL;DR: These results are believed to provide a basis for further studies with drugs or drug combinations that can influence hypothalamic and/or pituitary activity to promote mammary tumor regression, and thus serve as a possible alternative to endocrine ablative procedures.
Abstract: Sprague-Dawley rats bearing DMBA-induced mammary tumors were hypo-physectomized or injected with ergocornine or with ergocornine plus reserpine. Each treatment caused a prompt and prolonged regression of the tumors. Hypophysectomy was shown to be more effective in promoting tumor regression than treatment with ergocornine alone. However, reserpine administered in combination with ergocornine produced mammary tumor regression not significantly different from that obtained after hypophysectomy. These results are believed to provide a basis for further studies with drugs or drug combinations that can influence hypothalamic and/or pituitary activity to promote mammary tumor regression, and thus serve as a possible alternative to endocrine ablative procedures.
TL;DR: It was concluded that the response of the embryonic adrenal gland to growth stimulating agents was mediated via the anterior pituitary.
Abstract: Possible interactions between the anterior pituitary and the adrenal gland in the embryonic chick were investigated. Hypophysectomy by partial decapitation, and treatment of embryos with dexamethasone phosphate (a potent corticosteroid) both significantly reduced the growth of the adrenal gland, indicating a dependence of the adrenal gland on the pituitary for normal growth and the potential for negative feedback between the adrenal and the pituitary.
The hyperplasia of the host adrenal gland known to follow injection of homogenates of adrenal glands was inhibited when homogenates were injected into embryos whose ACTH production had been inhibited by dexamethasone. It was concluded that the response of the embryonic adrenal gland to growth stimulating agents was mediated via the anterior pituitary.
TL;DR: Twenty-seven patients with disseminated carcinoma of the prostate underwent adenohypophysectomy by either open craniotomy or stereotaxic cryohypophsectomy and growth hormone assay is a useful index of the adequacy of hypophy sectomy.
Abstract: Twenty-seven patients with disseminated carcinoma of the prostate underwent adenohypophysectomy by either open craniotomy (8 patients) or stereotaxic cryohypophysectomy (19 patients). All patients had growth hormone assay following insulin-induced hypoglycemia during the preoperative (control) period and twice during the postoperative (experimental) period. In the postoperative tests, a 73% or greater suppression of growth hormone levels following hypoglycemia correlated with significant clinical remission and prolongation of survival. The minimal degree of growth hormone suppression consistent with clinical remission and extended survival was shown to be between 22% and 73% (as compared with preoperative control values). Subtotal hypophysectomy is adequate to achieve significant clinical remission and extended survival. Growth hormone assay is a useful index of the adequacy of hypophysectomy.
TL;DR: The data demonstrate that in posthypophysectomy-regressed testes 3H-progesterone metabolism does not revert to that observed in fetal testes or testes from immature animals, and suggest that the 20α-hydroxysteroid oxidoreductase activity may be influenced by gonadotropins.
TL;DR: Histological examination of the amputated tails of 17 hypophysectomized newts revealed abnormal and extremely retarded regenerates; four of them exhibited total inhibition of regeneration, which suggests a possible involvement of the pancreas in tail and limb regeneration in the adult newt.
Abstract: Histological examination of the amputated tails of 17 hypophysectomized newts revealed abnormal and extremely retarded regenerates; four of them exhibited total inhibition of regeneration. Thus, under the conditions of hypophysectomy, normal tail regeneration does not ensue in the adult Diemictylus viridescens . Also, hypophysectomy adversely affects the normal histology of both the endocrine and exocrine parts of the pancreas, as observed by the atrophy of the gland in all hypophysectomized cases. Presumably, the normal function of the gland was altered. This relationship between hypophysectomy and the atrophic pancreas suggests a possible involvement of the pancreas in tail and limb regeneration in the adult newt.
Journal Article•
TL;DR: Endocrine hormones were found to mediate the rapid leukocyte repopulation of peripheral blood that occurs within 6 hr of an intraperitoneal injection of cortisol in intact or adrenalectomized rats.
Abstract: Endocrine hormones were found to mediate the rapid leukocyte repopulation of peripheral blood that occurs within 6 hr of an intraperitoneal injection of cortisol. The thymus and lymph nodes both participate in the proliferative response; the degree of leukopenia and the rate of leukocyte repopulation were both decreased after removal of thymus or lymph nodes. Splenectomy, however, did not alter the rate of leukoycte repopulation. The leukocyte count decreased more rapidly in adrenal—demedullated than in intact or adrenalectomized rats, but the time course of leukocyte repopulation was the same in each group. Hypophysectomy, but not thyroidectomy, prevented leukocyte repopulation within the 6–hr period. 3H—thymidine incorporation into DNA of lymph nodes and thymus, but not spleen, was significantly less in hypophysectomized than intact rats. Evidence for an increased concentration of a hormone that promotes leukocytic proliferation was found in plasma of intact cortisol—treated rats; the uptake of 3H—thymi...