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PubMed1986

Lipid deposition after hypophysectomy and growth hormone treatment in the sheep fetus.

Fifteen sheep fetuses hypophysectomized around 115 days gestation (term 150 days) were treated with growth hormone (GH), adrenocorticotrophin (ACTH) or triiodothyronine (T3) by continuous intravenous infusion. At normal or caesarian delivery, about 149 days gestation, body weights and dissectible internal brown fat and subcutaneous white fat depots were compared with seven control hypophysectomized fetuses and four sham-operated controls, the latter groups receiving no hormone infusions. Hypophysectomy caused the appearance of a large persistent depot of subcutaneous fat which was unaffected by ACTH or T3 infusion. Treatment with ovine pituitary GH resulted in the disappearance of this depot which was also absent from the sham-operated controls. Although the GH source was not subjected to extensive purification, there was very little contamination with prolactin or TSH, suggesting that GH itself has a major role in the control of lipid metabolism in the fetus.

Adipose Tissue↗
PubMed1987

Hypophysectomy increases vasoactive intestinal peptide-stimulated cyclic AMP generation in the hippocampus of the rat.

In investigating the feedback effects of circulating hormones on the brain, we showed previously that adrenalectomy (ADX) increases vasoactive intestinal peptide (VIP)-stimulated cAMP generation in slices from rat hippocampus, a brain structure with high levels of glucocorticoid receptors. This effect is reversed by replacement with glucocorticoids such as dexamethasone (DEX) and corticosterone (CORT). Here we report that, like ADX, hypophysectomy (HYPOX) also elevates VIP-stimulated cAMP generation, compared with sham-operated controls. Moreover, like glucocorticoid replacement, administration of ACTH to HYPOX rats causes a decrease in cAMP stimulation by VIP. Furthermore, ACTH had no effect when given to HYPOX + ADX rats, indicating that the effects of ACTH require the presence of adrenal steroid secretion. However, we find that ACTH may have a permissive role in this glucocorticoid effect because, in the absence of the pituitary, DEX treatment does not decrease VIP-stimulated cAMP levels in the hippocampus. In addition, hippocampal beta-adrenergic-stimulated cAMP accumulation was not suppressed by DEX treatment of HYPOX rats, which again is different from the effect of DEX treatment on ADX animals. These results are discussed in terms of possible synergism between pituitary hormones and steroid hormones in exerting feedback actions on brain function.

Adrenalectomy↗
PubMed1988

Hypophysectomy and adrenalectomy decrease Ca2+-induced swelling of rat liver mitochondria.

Hypophysectomized rats showed significant modifications in Ca2+-induced swelling and MgATP-induced contraction of liver mitochondria. Two-three months after operation, maximal swelling (MS), rate of swelling (VS), maximal contraction (MC) and rate of contraction (VC) were decreased by 77 (MS), 83 (VS), 79 (MC) and 62 (VC) % (in all cases P less than 0.05 as compared with normal rat mitochondria). Treatment of hypophysectomized rats with bovine pituitary extract, for two weeks, counteracted the effect of hypophysectomy, whereas treatment with bovine growth hormone was ineffective. Adrenalectomy produced similar though less extensive modification of Ca2+-induced swelling but failed to affect the MgATP-dependent mitochondrial contraction. Substrate oxidation by hypophysectomized or adrenalectomized rat mitochondria showed no modification of the energy-yielding mechanisms, capable of explaining the observed changes in mitochondrial swelling.

Adrenal Glands↗
PubMed1987

Effect of diabetes, adrenalectomy and hypophysectomy on D-3-hydroxybutyrate dehydrogenase activity and substrate oxidation by rat mitochondria.

In good agreement with previous observations, D-3-hydroxybutyrate dehydrogenase (OHBD) activity in disrupted liver mitochondria decreased significantly in chronic diabetic rats, whereas insulin treatment prevented this decrease. Similar effects were observed with kidney mitochondria. Adrenalectomy increased OHBD activity in liver and brain mitochondria from normal rats and in liver mitochondria from diabetic rats. Corticosterone depressed OHBD activity in liver mitochondria of normal rats and restored the normal level of OHBD in adrenalectomized rats. Hypophysectomy increased OHBD activity in normal rats, this effect being further increased by growth hormone administration. D-3-hydroxybutyrate (OHB) oxidation by liver mitochondria from diabetic, adrenalectomized or hypophysectomized rats varied as expected from OHBD activity in disrupted mitochondria, but to a relatively lesser degree. Submitochondrial particles from diabetic rats showed significant diminution in OHB-, succinate- and NADH-oxidase activities, whereas mitochondria from diabetic rats oxidized succinate and L-malate + L-glutamate at a slower rate than the corresponding controls.

3-Hydroxybutyric Acid↗
PubMed1987

[Ultrastructural changes in the pinealocytes of the rat in the late period after hypophysectomy].

Changes in the ultrastructure of epiphyseal pinealocytes were examined 3 weeks after hypophysectomy in infantile male rats in order to study functional relations of pineal gland with the hypothalamo-hypophyseal system. In hypophysectomized animals the functional activity of pineal secretory cells was found to decrease. Besides, the symptoms of suppression of biosynthetic processes and energy metabolism, as well as lipid infiltration and degradation of intercellular contacts, were observed.

Animals↗
PubMed1978

[Changes in the hypothalamo-hyophyseal neurosceretory system of mammals following pituitary stalk transection and hypophysectomy].

Hypophysectomy and pituitary stalk section result in dramatic morpho-functional changes in all parts of mammalian hypothalamo-hypophyseal neurosecretory system. Reorganization of the hypophyseal stalk consists of several interconnected but differing in time processes. Simultaneously with the developing traumatic changes (degeneration of the sectioned neurosecretory fibers, secretory disorders) proliferation of pituicytes with characteristic phagocytic activity is observed. A little bit later, intensive mitotic division of endothelial cells and capillary formation piercing the stalk periphery begins. At the same time, a new way for blood outflow from the capillaries of the primary portal plexus into the synuses of the brain pias is restored. Degenerated neurosecretory fibers are gradually substituted by regenerating fibers forming a dense network in heavily vascularizated stalk parts. As differentiation of endothelial cells and regeneration of neurosecretory fibers procede, axovasal contacts are gradually forming. At that time the hypophyseal stalk begins functioning as a neurohumoral organ but morpho-functionally less perfect than the posterior hypophyseal lobule. In the median eminence of the operated animals, unlike the intact ones, neurosecrete is accumulating around the capillaries of the portal plexus. Mechanical damage of neurosecretory fibers during the operation results in degeneration of a greater number of neurosecretory cells in the supraoptical and paraventricular nuclei. Preserved cells have an increased functional activity because of neurohormonal deficiency in the organism. As a result of the structural changes mentioned, diabetes mellitus develops, subsiding gradually with time course.

Adaptation, Physiological↗
PubMed1986

Effect of chicken growth hormone, triiodothyronine and hypophysectomy in growing domestic fowl.

Hypophysectomy in growing chicks was followed by reduced body and skeletal (shank-toe length) growth. In addition decreases were observed in tibia length and weight (although the proximal growth plate often contained more cartilage and was less uniform in its thickness), the plasma concentrations of immunoreactive-Somatomedin C (IR-SmC) and free fatty acids and weight for the heart, liver, pectoralis, thymus, and bursa Fabricus. The effect of triiodothyronine (T3) and purified chicken growth hormone (GH) on body and other growth was examined in hypophysectomized chicks. Body and skeletal growth (as estimated by respectively the increases in body weight and shank toe length in 24 days) were increased by the administration of T3 (either as injections or in the diet). T3 also increased tibia weight and length and returned the proximal growth plate thickness to that found in intact controls. Similarly T3 administration was followed by increases in the weights of the heart, liver, thymus, and bursa Fabricus. However plasma concentrations of IR-SmC were unaffected by T3 treatment. Chicken GH at a dose of 100 micrograms/kg stimulated aspects of growth somewhat with injections of chicken GH being followed by a slight increase in tibia length and a substantial increase in thymus weight. Chicken GH also increased plasma concentrations of IR-SmC and free fatty acids. Combination T3 and chicken GH treatment did not cause greater growth than observed with T3 alone. An exception to this being the greater weight of the bursa Fabricus in the chicks receiving T3 and GH than T3 alone. Intact male chicks which received injections of chicken GH (10 micrograms) between 1 and 14 day old had slightly greater body weight at 31, 38 and 44 days old relative to vehicle injected chicks.

Aging↗
PubMed1977

Influence of acute hypophysectomy on the natriuresis of dogs submitted to expansion of the extracellular fluid volume.

Three days after creating an access to the turcica on the sphenoid bone, twelve anesthetized mongrel dogs, after control collections, were submitted to extracellular volume expansion with saline. Thereafter, maintained constant the rate of saline infusion, the dura-mater covering the pituitary gland was incised in all dogs, the hypohysis being removed in seven and remaining untouched in the other five dogs. Pharmacological doses of pitressin, glycocorticoids and mineralocorticoids were administered to all dogs. It was shown, for the same filtered sodium load(p is greater than 0.05), that hypophysectomy produces a significant reduction (p is less than 0.05) in urinary sodium excretion previously elevated by the extracellular volume expansion, while durostomy only, without removal of th hypophysis, did not change (p is greater than 0.05) the rate of sodium excretion. Thus, the pituitary gland could be considered as contributing to natriuresis during extracellular volume expansion, all other factors related to this expansion remaining constant in both, hypophysectomized and sham operated dogs.

Animals↗
PubMed1983

Effects of early hypophysectomy in the aging rat ovary. Ultrastructural study on regression and on delayed epithelial proliferation in the interstitial tissue.

This report describes the fine structure of the "wheel" cells and of epithelial structures which both characterize the interstitial tissue of hypophysectomized and intact senescent rats. The regressive changes induced in normal ovarian interstitial cells of 25-26 day-old hypophysectomized rats were studied from 7 days to 15 months after the operation. They mainly consist in a rapid cytoplasmic dedifferentiation of these steroidogenic cells which, by one month after hypophysectomy, could be only identified by their specific nuclear pattern ("wheel" cells). Further changes of their organelles are only quantitative. These interstitial cells become perennial cells with no ultrastructural signs of senescence. In one year-old animals, the presence of both epithelial testis-like tubes and epithelial cellular cords provides evidence that these structures represent two different morphological arrangements for a similar cellular aspect. Unlike established "wheel" cells, these epithelial structures are evolutive and the thickening of their basement membrane can be considered as an age criterion. The follicular origin of the testis-like tubes and the complex formation of the cords are discussed in the light of our previous photonic study and compared with similar structures occurring in the senile rat ovary and in other situations.

Aging↗
PubMed1982

Effect of hypophysectomy and starvation on the fine structure of vitellogenic oocytes in the newt, Triturus pyrrhogaster (Laur).

Hypophysectomy and starvation in Triturus pyrrhogaster result in a similar ultrastructural pattern of follicular atresia. The first detectable change in the oocytes is decrease in the size and number of microvilli. Subsequently the yolk precursor bodies (YPB) disappear from the micropinocytotic vesicles and the mitochondria degenerate. Finally the yolk platelets undergo decomposition. The smaller yolk platelets disintegrate by granulation, vacuolation and lobule formation. The larger platelets, after losing their superficial layer and the inner crystalline lattice, are surrounded by a laminated membrane complex. The pattern of yolk breakdown is comparable to that during development. A rather delayed effect is observed on the nucleolus of the oocytes. Pigment granules seem to play an important role in the proteolysis of the yolk.

Animals↗
PubMed1980

[Experiences on stereotaxic hypophysectomy for recurrent breast carcinoma; with particular reference to its pain relief (author's transl)].

Stereotaxic hypophysectomy was performed in nine patients with advanced breast carcinoma. Only one patient showed an objective remission in the form of decreased size of the chest wall ulcer after the operation. However, all but one patient did get relief of pain lasting for months. In one of these cases, where hypophyseal ablation was carried out under local anesthesia, pain relief was ascertained immediately after the ablation, i.e., during the operation. Such an instantaneous pain relief, which to the author's knowledge has never been described elsewhere, was considered to be the result of an influence on the hypothalamus rather than the pituitary itself. Mechanism of lasting pain relief was ascribed to endorphins which have recently attracted attention as endogenous peptides with opiate-like activities. Pituitary ablation of the present authors were noted to be incomplete either seen from hormonal assessment or from morphological evaluation. It was stressed that significant pain relief could be gained by the apparently incomplete hypophyseal ablation, whereas complete destruction does not necessarily guarantee a hundred percent relief of pain. A deduction was made that although endorphins may play an important role in alleviating pain, integrity of its productive system and/or its receptors could also be important as well. Stereotaxic hypophyseal ablation might be the procedure of choice in certain patients with advanced breast carcinoma suffering from excruciating pain.

Breast Neoplasms↗
PubMed1982

[Effect of hypophysectomy on survival, weight gain and food intake in chickens].

Hypophysectomy has been performed in 1, 20, 50, 90 and 110-day-old chickens. The effect of the pituitary ablation depended on both the age and the sex of the birds. Chicks hypophysectomized on the day of birth survived no more than 5 days. In the other experimental groups, the later the operation was done, the longer the chicks survived, with some rare exceptions. Survival was generally better in females. The weight gain was significantly slower in 50-day-old hypophysectomized chicks than in the controls. In the 90-day-old operated animals, slackening of weight gain was less pronounced; a catch-up weight gain began at 24 weeks and reached the control levels at about 45 weeks. These differences were still less marked in 110-day-old hypophysectomized chickens in which the catch-up weight gain was faster. In all the hypophysectomized chicks, food intake was less than in the controls, but its utilization was better than in the controls, especially the pair-fed controls.

Aging↗
PubMed1981

Meningitis complicating transsphenoidal hypophysectomy.

The case records of 98 patients who underwent a transsphenoidal hypophysectomy between 1969 and 1979 were examined to establish the frequency of postoperative cerebrospinal rhinorrhea and meningitis. There were seven cases of rhinorrhea and six of meningitis following the procedure. Five of the six patients with meningitis had diabetes mellitus and three of the seven with rhinorrhea had meningitis; thus, both diabetes and rhinorrhea were established as significant risk factors (P less than 0.001) in the development of meningitis after this operation. There were two proven cases of meningitis due to anaerobic organisms and a further two suspected cases. The prophylactic use of antibiotics did not prevent the development of meningitis in this series of patients.

Adult↗
PubMed1980

[Plasma testosterone level and structure of the epididymis and accessory organs of the boar (Sus scrofa L.) after hypophysectomy followed by hCG gonadotropin administration].

Hypophysectomy of the boar resulted in a rapid drop in plasma testosterone level. hCG injections (400 IU/day) considerably elevated testosteronemia (up to 16.41 ng/ml). This effect was obtained either in the days following the operation or several months after (up to 134 days). In the latter case, the effect was temporary because the testosterone level dropped again after 15 days of injections. The sexual target organs (epididymis, seminal vesicle, prostate and Cowper glands) underwent structural change which, in the epithelium, corresponded to fluctuations in testosterone level. These effects were less marked in the cauda epididymis than in other target tissues. In various target organs, the conjunctivomuscular stroma developed after the operation; it did not regress at all, or incompletely, when the epithelia were stimulated indirectly by hCG, and began to hypertrophy when the hCG was no longer effective. Variations in stromal reaction were organ-dependent. When the hCG was administered for more than 14 days, it seemed to have a desensitizing effect; these mechanisms have been discussed.

Animals↗
PubMed1980

Effects of hypophysectomy and triiodothyronine on de novo biosynthesis, catalytic activity, and estrogen induction of rat liver histidase.

Synthesis of rat liver histidase is under multihormonal control; estrogen, glucocorticoid, and glucagon, via cAMP, induce this enzyme. By means of in vivo [3H]leucine incorporation into immunoprecipitated histidase, relative to that incorporated into total soluble protein, we have now demonstrated that de novo hepatic histidase synthesis, as well as catalytic activity, is selectively increased following hypophysectomy. Treatment of hypophysectomized rats with physiological levels of triiodothyronine (T3) diminished histidase synthetic rates and catalytic activities to normal levels, despite concomitant elevation in total soluble protein synthesis. Thyrotoxic doses of T3 further reduced histidase synthesis to barely measurable rates. Since thyroid hormone is under pituitary regulation, this hormone may be primary in the hypophyseal suppression of histidase. Estrogen does not induce hepatic histidase in the hypophysectomized rat. However, administration of the histidase suppressor, T3, or prolactin, which in itself has no effect on this enzyme, was ineffective in reinstating estrogen inducibility of histidase in the hypophysectomized animal. Thus, some as yet unknown hypophyseal agent is required for estrogenic inducibility of this liver enzyme.

Ammonia-Lyases↗