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PubMed1980

Recurrent Cushing's disease: successful treatment by pituitary irradiation or trans-sphenoidal hypophysectomy in two cases.

Two patients developed recurrent Cushing's disease 3 and 7 years after total bilateral adrenalectomy. In the first patient, a 65-year-old man, the adrenal tissue was not localized by radioactive cholesterol scintigraphy. Plain x-ray films of the skull revealed a normal sella turcica. Although clinical improvement resulted from the discontinuation of cortisone replacement therapy, urinary free cortisol levels remained elevated and the patient was treated with pituitary irradiation. Serum and urine cortisol levels gradually returned to normal. Four years after irradiation, the plasma adrenocorticotropic hormone (ACTH) concentration was elevated, but tomography of the sella turcica and urinary cortisol excretion remained normal. The second patient, a 41-year-old man, displayed elevated ACTH levels and x-ray evidence of a pituitary tumor at the time of recurrent Cushing's disease. After trans-sphenoidal hypophysectomy, the hypercortisolism abated and the ACTH concentration returned to normal. Adrenal scintigraphy frequently locates cortisol-secreting tissue in patients with recurrent Cushing's disease, and some investigators suggest treatment by the surgical removal of the adrenal remnant. Although the etiology of Cushing's disease is controversial, current evidence suggests that most cases result from ACTH-producing pituitary tumors. We suggest, therefore, that the anterior pituitary gland may be a more suitable target than the adrenal remnant for the treatment of recurrent Cushing's disease.

Adenoma↗
PubMed1986

Effects of hypophysectomy and growth hormone treatment on sex-specific forms of cytochrome P-450 in relation to drug and steroid metabolisms in rat liver microsomes.

Hypophysectomy decreased the content of a male specific cytochrome P-450, P-450-male, in male rats, while it expressed P-450-male and completely depressed a female specific cytochrome P-450, P-450-female, in female rats. Intermittent injections of human growth hormone (GH), which mimic the secretion in males, restored P-450-male in hypophysectomized (Hypox) male rats and partially restored P-450-female in Hypox female rats. Continuous infusion of GH, which mimics the female secretion pattern, into Hypox male rats caused a further decrease in P-450-male content, and it caused the expression of P-450-female. In Hypox female rats, the same treatment depressed P-450-male and expressed P-450-female to the level of an intact female. These results indicate that the diurnal changes in the pattern of serum growth hormone level regulate the expression of P-450-male and P-450-female. The activities of testosterone 2 alpha- and 16 alpha-hydroxylases were closely correlated to P-450-male content with the correlation coefficients (r) of 0.955 and 0.929, respectively. Benzo(a)pyrene hydroxylation was also correlated to P-450-male content (r = 0.850). Aminopyrine N-demethylation and propoxycoumarin O-depropylation were correlated to less extents (r = 0.692 and r = 0.720), while aniline hydroxylation and O-ethylresorufin O-deethylation were not correlated to P-450-male content. These results indicate that testosterone 2 alpha- and 16 alpha-hydroxylations are closely dependent, but the metabolism of a variety of drugs are dependent to different extents on P-450-male in rat liver microsomes.

Animals↗
PubMed1990

Rhinosurgical experience with the transseptal-transsphenoidal hypophysectomy: technique and long-term results.

Many modifications of extracranial transsphenoidal hypophysectomy exist, but knowledge of the rhinological implications of these procedures is rare. At our institution the transseptal approach is performed as a joint rhinosurgical and neurosurgical procedure. Three hundred nineteen patients were operated on from 1979 to 1984, 113 of whom had a rhinological follow-up for 5 years. Most of the complications were asymptomatic. Thirteen percent of the patients had septal perforations, 3.5% epistaxis, and 36% complained of mild dryness of the nose. An improvement in breathing was noted in 24% of the patients. There was no difference in rhinological complaints between patients who underwent the sublabial approach and those operated via a transnasal approach. Twenty percent of the patients operated on with the sublabial approach had additional temporary complaints in the upper lip; therefore, the transnasal-transseptal approach is currently our procedure of choice.

Adolescent↗
PubMed1975

Elevated serum growth hormone in protein-deprived rats, and decreased liver RNA after hypophysectomy.

Serum growth hormone was significantly higher in rats fed on a non-protein than on a 25% casein diet. In both dietary groups, hypophysectomy provoked a decrease in the RNA/DNA ratio of the liver, and, especially in the protein-deprived rats, a decrease in the RNA synthesis per liver cell, measured as the product of the RNA/DNA ratio, and the ratio of specific RNA activity to specific nucleotide activity, two hours after administration of [3H]orotic acid. In the protein-deprived rats, full reconstitution of these figures was obtained with a combination of growth hormone, hydrocortisone and triiodothyronine, but not quite with growth hormone alone. The possible role of growth hormone in protein deprivation is discussed.

Animals↗
PubMed1975

An improved technique for transauricular hypophysectomy and auto transplant of isolated pieces of pars intermedia tissue in the evacuated pituitary capsule of the rat.

An improved technique for transauricular hypophysectomy in rats, weighing 120-300 g, is described. This method can be used for transplantation studies, which is demonstrated by transplanting pars intermedia tissue into the evacuated pituitary capsule. Our technique has been carried out, successfully, in various laboratories. The success, however, depends upon the skill and care of the investigator.

Animals↗
PubMed1979

Gigantism associated with a pituitary tumour secreting growth hormone and prolactin and cured by transsphenoidal hypophysectomy.

An 18-year old male is reported who presented with a history of a growtn spurt over the year preceding his admission. His height was above the 97th percentile, and he had incompletely developed secondary sexual characters. Pituitary evaluation demonstrated a moderately elevated level of growth hormone (hGH) not suppressible by a glucose load and not stimulable by TRH or by L-DOPA. Serum prolactin (PRL) concentration was also increased while gonadotrophin, thyroid and adrenal function were all subnormal. There was clear radiological evidence of a large pituitary tumour with suprasellar extension and transsphenoidal total hypophysectomy was performed. A mixed chromophobe and acidophilic adenoma was found and both growth hormone and prolactin were demonstrable in different cells of the tumour by the immunoperoxidase technique. Post-operatively the patient has hypopituitarism and levels of growth hormone and prolactin have remained low or undetectable after 6 months. Thus early diagnosis and surgical treatment of gigantism of this mixed hGH-PRL secreting pituitary tumour was associated with a cure, which contrasts with the unfavourable outcome of many of the patients previously reported.

Adenoma, Acidophil↗
PubMed1979

Effect of hypophysectomy on mouse oocyte maturation in vitro.

There was no difference in frequency of maturation of oocytes obtained from mice hypophysectomized for 2 weeks compared to those from sham-operated or untreated (control) animals of the same age. By 7 weeks, and also at 12 and 17 weeks, the incidence of polar body formation in vitro was significantly reduced. The number of oocytes which remained meiotically inactive in culture was increased at 7, 12 and 17 weeks after hypophysectomy. This decrease in spontaneous oocyte maturation in vitro could be partly overcome by administering exogenous PMSG, oestradiol-17beta or PMSG + oestradiol-17beta, but not progesteron or hCG, to hypophysectomized mice.

Animals↗
PubMed1980

Effects of hypophysectomy and of LH administration on luteal phase plasma progesterone levels in the beagle bitch.

Luteal-phase progesterone levels in 5 beagle bitches fell to 0.3-0.4 ng/ml within 3-17 days after hypophysectomies on Day 10-50 of the cycle. Plasma progesterone in 6 bitches increased (P < 0.01) within 3 h after LH (100 microgram/kg) injection between Days 35 and 55 of the cycle. Normal luteal function in the bitch appears to require continuous pituitary trophic support perhaps involving LH.

Animals↗
PubMed1982

Effects of gonadotrophins, hypophysectomy and prostaglandin F-2 alpha on corpora lutea and ovarian follicles, and evidence for the presence of PGF-2 alpha receptors in the ovarian follicles and interstitium of non-pregnant guinea-pigs.

Simultaneous administration of hCG (but not FSH or prolactin) with PGF-2 alpha prevented the luteolytic effect of PGF-2 alpha after Day 9 of the oestrous cycle both morphologically and in terms of progesterone secretion in hysterectomized guinea-pigs. Hypophysectomy on Day 5 or PGF-2 alpha administration on Days 6--9 were not luteolytic, but their combined effect resulted in an advanced state of luteolysis as early as Day 9. When PGF-2 alpha was injected simultaneously with FSH or prolactin (but not hCG), the proportion of atretic antral follicles was significantly increased, although the total number of antral follicles remained unchanged. When PGF-2 alpha receptors were measured in the membrane fractions of luteal tissue and ovarian stromal, interstitial and follicular tissue obtained from cyclic animals, the concentrations were 22.75 and 36.26, and 62.60 and 96.26 fmol/mg membrane protein on Days 5 and 12, respectively. It is concluded that (1) LH protected corpora lutea against the luteolytic action of PGF-2 alpha up to Day 9 of the cycle, (2) PGF-2 alpha receptors were present in follicles, and (3) these receptors and PGF-2 alpha were involved in the development of the normal complement of Graafian follicles.

Animals↗
PubMed1986

Influence of hypophysectomy on the lifespan of the corpus luteum in the cyclic dog.

Five dogs were hypophysectomized on Day 4 and 9 on Day 18. Prolactin and LH stimulation tests showed that hypophysectomy was complete in 6 dogs only. In these dogs, the progesterone concentration was measured in the peripheral blood; it decreased sharply immediately after surgery. It regained normal values in 3 of the 4 dogs hypophysectomized on Day 4, and remained low in the 2 dogs hypophysectomized on Day 18. This indicates that, in the dog, luteal function is autonomous during a certain period. The luteal period of the 3 dogs hypophysectomized on Day 4 was shorter than that of control animals, although the time of onset of luteal regression appeared to be similar. This indicates that pituitary luteotrophic support is required during the second part of the oestrous cycle of the dog.

Animals↗
PubMed1990

Effect of long-term hypophysectomy on ovarian follicle populations and gonadotrophin-induced adenosine cyclic 3',5'-monophosphate output by follicles from Booroola ewes with or without the F gene.

Long-term (i.e. approximately 70 days) hypophysectomy led to a significant (P less than 0.05) reduction in ovarian weight but no reduction in the total number of antral follicles (greater than 0.1 mm in diameter). In hypophysectomized ++ Booroola ewes (N = 8) follicles were always less than or equal to 3 mm and in hypophysectomized FF Booroola ewes (N = 6) follicles were always less than or equal to 2 mm in diameter; in ewes of both genotypes follicles reached diameters which were approximately 40% of their predicted final size at ovulation. Under in-vitro conditions, follicles from the FF and ++ hypophysectomized ewes produced significant increases in cAMP within 1 h of exposure to gonadotrophins (P less than 0.05) although no genotypic differences in cAMP production were noted. We conclude that ovarian follicles in FF and ++ ewes have absolute requirements for pituitary hormone on reaching diameters of 2 mm and 3 mm respectively and that appreciable numbers of antral follicles in ewes of both genotypes remain responsive to pituitary gonadotrophins despite prolonged deprivation of these hormones.

Animals↗
PubMed1976

[Improved procedure for hypophysectomy of the mouse (author's transl)].

A practical procedure for hypophysectomy of the mouse by paraphyaryngeal approach has been developed by modifying the technics of Motizuki [5] and Lostroh and Jordan [4]. Postoperative care in C3H/He strain of female mice was also studied. The main points improved are as follows: (a) The dental drill bar made of a needle with 2mm outer diameter was devised for making a hole in the cranium (Fig. 2). The bar does not grind the cranium, but cuts it in the circle, resulting in speeding up of the operation and in little bleeding, since the hole is very small. (b) Special attention was paid in breathing of mice during the operation. A longitudinal midline incision of about 1cm was made in muscle encircled the trachea and a pinhole was made by sewing needle into the trachea. A small piece of cotton wool was put on the pinhole and covered by the muscle. It admirably keeps the tracheal hole open for breathing during operation (Fig. 1). (c) After the operation, the mouse was placed in a chamber filled with an atmosphere of 95% O2-5%CO2 gas until recovered, otherwise, all mice died in a few days after operation with inflamation of the lung. The temperature of the recovery chamber is recommended to be kept at about 28 degrees C for ensuring the resuscitation. The intraperitoneal injections of hydrocortone-acetate (0.25mg/0.1ml) just before and 2 days after operation further ameriolated the survival rate.

Animals↗
PubMed1992

Changes in rhythmicities of ambulatory and drinking activities after hypophysectomy in rats.

Effects of hypophysectomy on circadian rhythms of ambulatory and drinking activities in adult male rats were automatically recorded and investigated with a Gundai-type ambulodrinkometer. The rats were maintained under LL conditions following an LD condition. When free-running rhythms had stabilized, the rats were hypophysectomized. The rhythmicities of both activities became indistinct over the 2-4 weeks following surgery, and then gradually recovered. At this time phase shifts (phase advance) were observed in the hypophysectomized rats, while these changes were not observed in sham-operated rats. All rats entrained to lighting when kept under LD conditions again. These results suggest that the pituitary does not play an essential role in maintaining circadian rhythms, but does function as an important subordinal oscillator.

Animals↗
PubMed1975

Dynamics of insulin release by perfused hamster )Mesocricetus auratus) pancreases: effects of hypophysectomy, bovine and human growth hormone, and prolactin.

The hamster exhibits a biphasic pattern of insulin secretion; however, the dynamic response differs qualitatively from that of the rat in that there is a steady-state second release phase. A marked attenuation of insulin secretion as a result of hypophysectomy was observed after 3 weeks, but not after 2 weeks. This depression of insulin secretion was restored to near or above normal levels by bovine growth hormone, human growth hormone, and prolactin.

Animals↗
PubMed1976

Effects of oestradiol-18beta, hypophysectomy and age on cytoplasmic oestradiol-17beta receptor sites in rat testis interstitial tissue.

After administration of oestradiol-17beta to intact mature and immature rats, a decrease in the testicular concentration of specific oestradiol-binding sites was observed within 1 h. The binding capacity was replenished starting about 3 h after oestradiol administration and after 5 h the oestrogen receptor level had returned to control values. Exposure of intact animals to oestradiol-17beta for longer periods (up to 24 h) did not result in an increase of receptor levels in testicular cytosol. Mature animals which were hypophysectomized for periods of up to 10 days did not show a significant change in the number of specific oestradiol-binding sites in either total testicular tissue or dissected interstitial tissue. At 15 days or longer periods after hypophysectomy, an apparent increase in receptor concentrations in total testicular cytosol was observed due to a relative increase in the amount of interstitial tissue. A specific oestradiol-binding protein is present in plasma of immature male rats aged less than 30 days. This plasma protein could also be demonstrated in the cytosol of testes of immature rats. In contrast to the cytosol receptor, which shows a moderate affinity for diethylstilbestrol (DES), the plasma protein did not bind DES. The sedimentation values of the plasma protein and the oestradiol receptor were 4 S and 8 S respectively. These differences in characteristics made it possible to demonstrate the presence of the oestradiol receptor in addition to the binding protein in testicular cytosol of rats from 14 days of age onwards. The nuclear receptor for oestradiol-17beta could be demonstrated after incubation of testicular tissue of rats from 4 days of age onwards.

Age Factors↗
PubMed1977

Effect of hypophysectomy on p-aminohippurate transport kinetics in rat renal cortical slices.

Recent work on kidneys from hypophysectomized (hypox) rats has shown atrophy of the proximal tubules with no effects on the other parts of the nephron. We carried out experiments to determine whether the reduction of p-aminohippurate (PAH) is consistent with structural changes in the proximal tubule of hypophysectomized rats. Initial velocities of PAH uptake by renal cortical slices were found to be constant over 30 min of incubation at concentrations of PAH up to 0-5 mmol/1 for both control and hypox animals. Using kinetic analysis, it was found that both maximal velocity, Vmax, and the Michaelis constant, Km, were reduced in hypox animals, the relative reduction being similar for both parameters. Comparison between high Na (100 mmol/1) and low Na (6 mmol/1) media indicated that in both control and hypox rats, Vmax was significantly lower in low Na medium than in high Na medium, whereas Km was not changed. Efflux of PAH from pre-loaded tissue also showed a reduction in hypox animals. These results may indicate that hypophysectomy alters the capacity of PAH transport in renal cortical slices by (1) reducing the effective transport area or sites, and (2) by changing carrier-substrate affinity.

Aminohippuric Acids↗
PubMed1979

Somatomedin-like activity in plasma after foetal hypophysectomy or nephrectomy and in experimental intra-uterine growth retardation in sheep.

Plasma samples from pregnant ewes and their foetuses during the last quarter of gestation were assayed for somatomedin-like activity (SLA) using the procine costal cartilage assay. In maternal plasma, the mean potency (compared with pooled serum from six sheep) was 0.84 +/- 0.05 (S.E.M.) units/ml (n = 15). Somatomedin-like activity in the plasma of five control foetuses (0.91 +/- 0.1 units/ml) was similar to the maternal levels and did not change with gestational age. After foetal hypophysectomy the SLA in foetal plasma (0.37 +/- 0.05 units/ml, n = 4) was significantly less than in control animals. In two nephrectomized foetuses, the mean SLA in plasma (0.08 and 0.51 units/ml respectively) was less than in control animals. Retardation of intra-uterine foetal growth was induced by removal of endometrial caruncles before pregnancy in four sheep. The SLA in plasma from these foetuses was 0.38 +/- 0.05 units/ml (P less than 0.01 v. control animals). The results suggest that SLA in the foetus may be important in the regulation of foetal growth, but they also indicate that factors other than growth hormone may be important in the control of SLA in foetal plasma.

Animals↗
PubMed1980

Checking of hypophysectomy in the rat using longitudinal bone growth determined with tetracycline.

The longitudinal bone growth in 1922 consecutively hypophysectomized and surviving rats was determined with oxytetracycline. The longitudinal bone growth of proximal tibia during the first 15 postoperative days and the width of the fluorescent tetracycline band at 15 days after the operation were found to correlate well with the microscopical examination of serial sections of sella turcica. These growth parameters, when considered together, can be used as a means of screening whether hypophysectomy is complete. As a result microscopical examination of serial sections of the sella turcica to ascertain the completeness of the operation can be reduced to about the 10% of the animals where there remains some doubt.

Animals↗