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PubMed1978

[Change in the adrenal cortex of rats in stress after hypophysectomy, thyroidectomy and castration].

To elucidate factors producing destructive changes in the adrenal cortex under severe stress, the following experiments were performed: 1) severe combined stress (KC) including unilateral adrenalectomy and fixation in supin position for 24 h (control group); 2)hypophysectomy KC; 3) thyroidectomy KC; 4) bilateral orchiectomy KC; 5) injection of vitamine "E" for 14 days + KC. The adrenals were studied by a complex of morphometrical and histochemical methods. Hypophysectomy prevented estructive changes in the adrenal cortex under KC. This effect was not connected with hypofunction of the thyroid gland and the testes, as their excision (in rats without hypophysectomy) did not prevent the development of necrobiotic changes in the adrenal cortex. A suggestion is made on a "corticolytic" effect of ACTH which reveals itself under severe stress. Destruction of adrenocorticocytes is supposed to result from activation of peroxide oxidation of lipids. This is indirectly supported by a large number of lipofuscin containing cells, by decrease in the activity of alkaline phosphatase and ATPh-ase, by activation of acid phosphatase and also by decreasing alterative phenomena at the injection of vitamine "E".

Adrenal Cortex↗
PubMed1981

[Long-term results of surgical hypophysectomy for diabetic retinopathy (author's transl)].

Between 1969 and 1974, ten insulin-dependent diabetic patients underwent surgical hypophysectomy for rapidly progressive proliferative retinopathy endangering sight. Six to 11 years later, the 7 patients who survived had useful visual acuity and were leading a normal life. The long-term results of hypophysectomy on the eye could be observed in this series of patients with exceptionally long follow up: oedema had subsided, haemorrhagic exsudates and newly formed retinal vessels had disappeared, and the retinal had become hypovascular. However, argon laser photocoagulation has now considerably reduced the indications of surgical hypophysectomy.

Adult↗
PubMed1976

Effect of hypophysectomy on the synthesis of rat liver albumin.

Hypophysectomy of adult rats results in approximately a 50% decrease in the rate of albumin synthesis relative to total liver protein synthesis. This decrease is accompanied by a proportional decline in the number of albumin-synthesizing polysomes, as determined by the binding of 125I-Labeled anti-albumin antibody, and indirect immunoprecipitation of [3H]leucine-labeled albumin-synthesizing polysomes. Furthermore, this decrease is associated with an equivalent reduction in the amount of total membrane-bound polysomes, whereas total free polysomes show little quantitative change. The size of the specific albumin-synthesizing polysomes, as well as the size of the total polysomes, however, appear to be the same following hypophysectomy as in the normal untreated animal. These observations are consistent with the finding that the relative amount of albumin mRNA activity also decreases approximately 50%, as assayed in a heterologous cell-free protein-synthesizing system using exogenous liver RNA prepared from either isolated polysomes or total liver homogenates. The decrease in albumin production in the hypophysectomized rat, therefore, is apparently the result of a reduction in the amount of active albumin mRNA. The concomitant decrease in albumin-synthesizing polysomes appears to reflect a similar reduction in the amount of total membrane bound polysomes. Thus, a major physiological defect in hypophysectomy may be a preferential decline in membrane-bount polysomes accompanied by a reduction in mRNA levels, which is represented by the decrease in albumin synthesis.

Albumins↗
PubMed1998

[Radiosurgical hypophysectomy in painful bone metastases of breast carcinoma].

Radiosurgical hypophysectomy using Leksell gamma knife was performed to the patient with cancer pain from bone metastases of the breast cancer, relief of the pain was achieved. Patient survived 26 months after hypophysectomy. Review of the literature concerning relief of the pain after hypophysectomy is presented.

Adenocarcinoma↗
PubMed2002

Morphologic changes in the granular convoluted tubule cells of the mouse submandibular gland following hypophysectomy and hormonal replacement.

Morphological changes in the granular convoluted tubule (GCT) cells of the male mouse submandibular gland (SMG) were examined following hypophysectomy and hormonal replacement. Semithin sections stained with Heidenhain's iron hematoxylin showed that hypophysectomy severely regressed the GCT phenotype. Although only a few dispersed cells containing secretory granules were observed in the GCT segments under a light microscope, electron microscopy revealed that many regressed cells continued to constitutively elaborate apical secretory granules (although they were very small) and contained a euchromatic nucleus at the center of the cell, poor rough endoplasmic reticulum (RER) and Golgi apparatus in the perinuclear region, and well-developed basal infoldings. These findings suggest that hypophysectomy resulted in atrophy of GCT cells, but that they retained evidence of being secretory cells. 5 alpha-Dihydrotestosterone (DHT); 3,5,3'-triiodo- l-thyronine (T(3)); and dexamethasone (Dex) each enhanced the GCT phenotype of hypophysectomized males to some degree. Combined hormonal replacement with DHT + T(3) in hypophysectomized males restored a nearly normal male GCT phenotype with a full complement of secretory granules and rare basal infoldings, whereas T(3) alone induced a normal female-like GCT phenotype, with considerably abundant secretory granules and the usual short basal infoldings, in hypophysectomized male glands. Furthermore, Dex was found to synergistically enlarge secretory granules when administered with T(3) and/or DHT, although it was only weakly effective in enhancing the GCT phenotype when used alone. Taken together, the above findings confirmed that the GCT phenotype of the mouse SMG is regulated by the synergistic action of pituitary-dependent hormones.

Journal Article↗
PubMed1977

Differential responsiveness of central noradrenergic and dopaminergic neuron tyrosine hydroxylase to hypophysectomy, ACTH and glucocorticoid administration.

Hypophysectomy leads to a small increase in tyrosine hydroxylase activity of all brain areas containing noradrenergic neurons or tuberoinfundibular dopamine neurons, but nigroneostriatal dopamine neurons are not so affected. ACTH or corticosterone treatment inhibited this effect of hypophysectomy in some noradrenergic neurons and in tuberoinfundibular dopamine neurons. These data showing differential responsiveness of tyrosine hydroxylase in different brain areas are compatible with differences in regulation or molecular form of tyrosine hydroxylase in central noradrenergic and dopaminergic neurons. The disparity between increased hypothalamic tyrosine hydroxylase activity and decreased norepinephrine turnover following hypophysectomy may result from a change in the rate-limiting step to the hydroxylation of dopamine.

Adrenocorticotropic Hormone↗
PubMed1985

[Serum anti-protease activity in the evaluation of results of proton hypophysectomy].

The activity of the alpha 1-antitrypsin and alpha 2-macroglobulin were studied in 16 breast cancer patients and 25 hypophyseal adenoma patients prior to and at varying time after proton "hypophysectomy". A high alpha 1-antitrypsin level and a normal alpha 2-macroglobulin level were found in all the breast cancer patients. An increase in both blood serum inhibitors was detected in hypophyseal adenoma. The dependence of the alpha 1-antitrypsin content on a subclinical stage of generalized metastatic spread was revealed in the course of 2 years following "hypophysectomy" in the patients with disseminated breast cancer. In the hypophyseal adenoma patients the activity of both inhibitors returned to normal 1 year after treatment and remained within normal during 3 years of follow-up. It was regarded as a positive therapeutic effect. The above findings make it possible to propose the determination of the activity af alpha 1-antitrypsin in breast cancer and alpha 1-antitrypsin and alpha 2-macroglobulin in hypophyseal adenoma as an additional test for the evaluation of the results of proton "hypophysectomy".

Adenoma↗
PubMed1964

OBSERVATIONS ON THE FINE STRUCTURE OF LUTEIN CELLS. II. THE EFFECTS OF HYPOPHYSECTOMY AND MAMMOTROPHIC HORMONE IN THE RAT.

Corpus luteum formation was induced in 26-day-old rats which were subsequently hypophysectomized and injected with mammotrophic hormone (MH, LTH). Sections of corpora lutea from these animals were examined with the electron microscope and compared with similarly prepared (Caulfield's fixed, Araldite embedded) corpora from normal pregnancy and from controls, the latter consisting of corpora prior to hypophysectomy and corpora from uninjected rats 7 to 14 days after hypophysectomy. Lutein cells from corpora lutea of injected animals and of normal pregnancy are characterized by abundant, tortuous, tubular agranular endoplasmic reticulum and by mitochondria, many of which are disc-shaped with dense matrices and both villiform and lamelliform cristae. The endoplasmic reticulum is most abundant in lutein cells from pregnant animals, in which cells it is in the form of thin, highly tortuous tubules. The form of the lipid droplets seen in cells of stimulated animals varies greatly. Marginal foldings of the lutein cells on the perivascular space were found in all instances. Lutein cells from hypophysectomized animals have a less highly developed agranular endoplasmic reticulum. The mitochondria have irregular outlines and a relatively lucid matrix. The lipid droplets in these cells show less tendency to be extracted, but are not so large or abundant as in the cells of onset controls. Granules believed to contain lipid pigments are common in the lutein cells of these control animals. It is suggested that lutein cells from corpora lutea which are actively secreting progesterone may be readily distinguished from lutein cells from non-active corpora by means of the multiple characteristics enumerated. It is further suggested that mammotrophic hormone has a general effect on the metabolism of lutein cells rather than solely affecting a specific organelle, the abundance or composition of which may be the limiting factor in the production of progesterone.

Animals↗
PubMed1959

Hypophysectomy for palliation of breast cancer with especial reference to surgical technique.

In a series of 19 patients who had hypophysectomy for palliation of cancer of the breast, all had striking relief of pain. Objective evidence of remission of disease was observed in ten patients. The survival time after operation averaged 19.8 months for patients who had remission and 2.1 months for patients who did not. Results were better in patients who had had cancer for a long time before operation than in those who had had the disease a relatively short time. Also it was noted that results were better in patients who had had preoperative response to endocrine therapy than in those who had not. Hence these factors may be considered in selection of patients for hypophysectomy.

Breast Neoplasms↗
PubMed1985

External rhinoplasty approach to transsphenoidal hypophysectomy.

The history of transsphenoidal hypophysectomy demonstrates the soundness of the basic concept of approaching the sella turcica in a midline fashion through the nose. Conceptually, it has not been eclipsed since first evolved by Cushing in the early part of this century. The surgical advances since Cushing's time have been major refinements in instrumentation and minor refinements of his basic technique. The external rhinoplasty approach is such a refinement. We have used this technique in a two-year period between June 1982 and June 1984 on 14 patients. We have found this technique for transsphenoidal hypophysectomy to be a simple, reliable, rapid technique for exposing the septum and the floor of the nose. It provides excellent exposure to the sphenoid sinus and pituitary gland without loss of nasal tip projection or other cosmetic deformity.

Adult↗
PubMed1977

Insulin-dependent diabetes mellitus. Sudden onset following hypophysectomy in an acromegalic patient.

A euglycemic woman with acromegaly contracted conspicuous hyperglycemia two hours following transphenoidal hypophysectomy. Insulin therapy was initiated and has by necessity been continued. The development in the immediate postoperative period of blood glucose levels ranging from 300 to 500 mg/dl was totally unexpected, as the levels on the preoperative oral glucose tolerance test were normal. No explanation for this sudden development of hyperglycemia is apparent. Therefore, frequent monitoring of the blood glucose level is necessary in all acromegalic patients following hypophysectomy, even if they are euglycemic prior to surgery.

Acromegaly↗
PubMed1980

Studies of the goitrogenic and tumorigenic effect of two goitrogens in combination with hypophysectomy or thyroid hormone treatment.

The influence of hypophysectomy, triiodothyronine (T3), and thyroxine (T4) on the goitrogenic and tumorigenic activity of methylthiouracil (MTU) and 1-methyl-2-mercapto imidazol (MMI) was studied in rats. Hypophysectomy effectively prevented the development of thyroid hyperplasia and adenomas in MTU-treated animals. T3 reduced or abolished the weight loss of goitrogen-treated animals, and prevented the development of thyroid hyperplasia, adenomas, and pulmonary metastatic nodules. The effect of T4 was less pronounced, especially in MTU-treated animals. This hormone failed to neutralize the goitrogenic effect of MTU but it did reduce significantly the incidence of thyroid adenomas and prevented the appearance of pulmonary lesions. The biological effect of the thyroid hormones correlated with their effect on the serum levels of TSH, T3, and T4. The observations are compatible with the assumption that the tumorigenic effect of the two goitrogens depends upon a state of imbalance between TSH and T3.

Adenoma↗
PubMed1991

Severe fibromyalgia after hypophysectomy for Cushing's disease.

We report a case of fibromyalgia occurring after hypophysectomy for Cushing's disease. Clinical examination revealed tender points at 12 of the 18 tender point sites described in the American College of Rheumatology 1990 criteria for the classification of fibromyalgia. The cause of fibromyalgia remains unknown. In our patient, hypophysectomy may have played a role by disturbing endorphin secretion and pain modulation.

Cushing Syndrome↗
PubMed1976

Transsphenoidal hypophysectomy: a laboratory approach and commentary.

A laboratory technique for learning and practicing the transsphenoidal approach to hypophysectomy is described. The procedure utilizes a sphenoid block with the sella turcica at its center taken from a cadaver skull. The laboratory approach stimulates the operative technique, including the use of standard instruments designed for transsphenoidal hypophysectomy. Commentary on the historical background and applications of the transsphenoidal approach to the sella turcica is presented.

Humans↗
PubMed2001

Effect of hypophysectomy and growth hormone replacement on the modulation of p450 expression after treatment with the aromatic hydrocarbon ethylbenzene.

Pituitary status has a significant effect on the expression of several cytochrome P450 enzymes. The goal of this study was to examine the role of pituitary input on the modulation of CYP2C11 and CYP2B after treatment with the aromatic hydrocarbon ethylbenzene (EB). Intact, hypophysectomized (HX), and HX rats supplemented with pulsatile growth hormone (GH) were treated with corn oil or EB and the effects on hepatic P450 expression were determined. Hypophysectomy caused a 50% decrease in CYP2C11 protein in untreated rats, whereas GH supplementation returned protein to control levels. EB administration also decreased CYP2C11 protein in intact rats; however, this decrease was not observed after EB treatment in HX or HX + GH groups. CYP2C11-dependent testosterone 2alpha-hydroxylation followed a similar pattern as CYP2C11 protein, except that the activity was only partially restored by GH replacement. CYP2B levels were also substantially influenced by hypophysectomy. Intact rats exhibited a 100-fold increase in CYP2B1 mRNA, reaching a maximum 12 h after EB administration. A much smaller response (ca. 20-fold) was observed in HX rats, reaching a maximum 24 h after EB treatment. This effect was not reversed by GH supplementation. The half-life for EB was significantly increased from 8 h in intact rats to 14 h in HX rats, suggesting higher plasma EB concentrations after EB administration to HX rats. These results indicate that CYP2C11 and CYP2B become less responsive to EB-dependent modulation in HX rats, a response that cannot be explained simply by absence of GH or by altered EB pharmacokinetics in HX animals.

Animals↗
PubMed1989

Oxytocin-induced penile erection and yawning in male rats: effect of neonatal monosodium glutamate and hypophysectomy.

Penile erection and yawning induced by the intracerebroventricular (ICV) injection of oxytocin (10-1000 ng) was studied in hypophysectomized rats and in rats neonatally treated with monosodium glutamate (MSG), a treatment that depletes hypothalamic opiomelanocorticotropin-derived peptides without altering their pituitary and circulating concentration. Oxytocin effect was strongly reduced by hypophysectomy, but not by neonatal MSG. Testosterone replacement (50 micrograms/kg/day for 23 days) partially reversed the effect of hypophysectomy on penile erection, but not on yawning. The present results suggest that oxytocin does not induce penile erection and yawning by releasing an ACTH-derived peptide from hypothalamic opiomelanotropinergic neurons, and that the pituitary gland exerts a permissive role on the expression of the above behavioural responses induced by oxytocin.

Animals↗
PubMed1989

Muscle regeneration. The effect of hypophysectomy on cell proliferation and expression of insulin-like growth factor-I.

Against the background of the importance of growth hormone (GH) for normal muscle growth, a study was performed to investigate whether lack of GH after hypophysectomy affects the cell proliferation and the local production of insulin-like growth factor-I (IGF-I) in the early stages of muscle regeneration in adult rats. The level of IGF-I in the serum of hypophysectomised rats was reduced to about 30% of that of controls. The incorporation of [methyl-3H]thymidine into the regenerating muscle showed a peak 6 days after the operation and then gradually declined to the end of the period of study 30 days after initiation of regeneration by ischemic necrosis. The DNA content rose to a maximum level after 6-8 days, and remained high after 30 days. There was no major difference in the incorporation of [3H]thymidine in regenerating muscle of hypophysectomised and control rats, but the DNA concentration in the regenerating muscles of hypophysectomised rats was significantly reduced after 30 days. There was a corresponding reduction in the number of nuclei per muscle fibre, indicating that hypophysectomy has a small effect on the cell proliferation during the early stages of muscle regeneration. Immunohistochemical demonstration of IGF-I in the regenerating muscle revealed the transient presence of immunoreactive material in satellite cells and myotubes after 6 to 8 days of regeneration but no immunoreactivity after 30 days. No obvious difference was observed between hypophysectomised and control rats, indicating that the endogenous production of IGF-I in regenerating skeletal muscle can occur independently of GH.

Animals↗
PubMed1979

Hypophysectomy-induced inhibition of augmented acetylcholine responses of the rat bowel following adrenalectomy and/or whole body irradiation.

Functional changes in the intestinal responsiveness to a fixed dose of acetylcholine were studied in muscle strips removed from young adult male rats previously exposed to whole body gamma radiation. In the irradiated rat the responsiveness to a fixed dose of acetylcholine was found to be augmented in the small intestine but not in the colon. Similar motor patterns for the small intestine were found when muscle strips from adrenalectomized rats were studied. Preradiation adrenalectomy further exaggerated the post-radiation sensitivity of the rat small intestine to acetylcholine. Hypophysectomy prior to either adrenalectomy and/or whole body radiation was associated with an absence of augmented small intestinal motor activity following administration of acetylcholine. The response of the large bowel to acetylcholine, however, was not modified by adrenalectomy and/or hypophysectomy. These observations suggest an endocrine component to the acute 3--5 day intestinal radiation syndrome.

Acetylcholine↗