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PubMedDate not supplied

The use of infraorbital nerve block for postoperative pain control after transsphenoidal hypophysectomy.

OBJECTIVES: The transsphenoidal approach for pituitary resection is often used for a suprasellar tumor. The use of infraorbital nerve block for pain control in the postoperative period is described in this case report. CASE REPORT: An 11-year old male was scheduled for a transsphenoidal approach to a pituitary tumor. After induction of general anesthesia and placement of an endotracheal tube, bilateral infraorbital nerve blocks (maxillary division of the trigeminal nerve) were performed using an intraoral approach. This block was repeated at the conclusion of surgery. The patient was very comfortable in the postoperative period without need for additional analgesia. CONCLUSIONS: Bilateral infraorbital nerve blocks may provide adequate pain control following transsphenoidal hypophysectomy. The avoidance of opioids may allow better neurological examination following major neurosurgical procedures.

Child↗
PubMed2006

Follicle-stimulating hormone treatment reverses the effect of hypophysectomy on cell proliferation in the chicken embryo ovary.

The present study evaluated the effect of FSH treatment on ovarian cell proliferation in the hypophysectomized chicken embryo. Hypophysectomy (Hx) was performed by the partial decapitation technique. Two series of experiments were performed: (a) Hx embryos were treated at 8 days of development with recombinant human FSH (rhFSH) and evaluated at 9 days by measuring BrdU incorporation; (b) Hx embryos were injected with rhFSH and rhCG at 9 days of development and the proliferation rate was measured at 13 days. The presence of mRNA for FSHR and LHR in the ovary of control and Hx embryos was demonstrated by RT-PCR analysis. There was a decrease in the percentage of BrdU labeled cells in the absence of hypophysis at 9 and 13 days of incubation. The decrease was reversed with rhFSH treatment. This effect was observed in the ovarian surface epithelium and the somatic cells of the cortex and the medulla in the 9-day-old embryo. Moreover, the number of somatic, steroidogenic, and germ cells was reduced at 13 days of incubation in the Hx embryo; when treated with rhFSH the number of cells increased to the level of controls. In another experiment, ovaries of 9-day-old chicken embryos were organ cultured for 48 h in a serum-free medium with rhFSH and rhCG separately. The proliferation index was incremented by rhFSH compared to control and rhCG-treated embryos. Therefore, FSH stimulates somatic cell proliferation in the chicken embryo ovary as early as 9 days of development.

Animals↗
PubMed2002

Sexual dimorphic expression of mouse hepatic CYP2B: alterations during development or after hypophysectomy.

The constitutive expression of CYP2B mRNA in the livers of mice in the prepubertal stage was sex-independent, with CYP2B9 as the principal isoform. During the maturation stage, CYP2B10 was expressed in both sexes, whereas CYP2B9 was diminished markedly in the males, resulting in a sexually dimorphic expression in adult mice. Hypophysectomy eliminated the sexual dimorphism in the mouse CYP2B subfamily by markedly increasing the expression of both CYP2B9 and CYP2B10 in males to levels similar to those in females.

Animals↗
PubMed1984

Medical hypophysectomy: I. Dose-response using a gonadotropin-releasing hormone antagonist.

The hypothalamic-pituitary-ovarian axis can be "dissected" in a nonsurgical and reversible fashion by the administration of a potent gonadotropin-releasing hormone (GnRH) antagonist. We created a transient, functional lesion at the level of the pituitary gonadotrope by using a potent GnRH antagonist ([ Ac- pClPhe1 , pClDPhe2 , DTrp3 , DArg6 , DAla10 ]-GnRH). In long-term castrate cynomolgus monkeys, doses of 0.05 to 2.0 mg/kg/day intramuscularly were administered for a total of 32 days. At doses up to 0.2 mg/kg/day, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in circulation were only moderately suppressed; these subjects responded to an estradiol challenge by manifesting an LH elevation or surge within 48 hours. At doses of 0.5 to 1.0 mg/kg/day, FSH and LH secretion was suppressed to or below the limits of assay detection within 7 days, remaining in a severely hypogonadotropic state for the remainder of the treatment interval. Using 2 mg/kg/day, estradiol-positive feedback for midcycle-like LH/FSH surges was fully inhibited. This suppression of gonadotropin secretion was rapidly reversible, in that circulating gonadotropin levels had returned to pretreatment castrate levels within 60 days after termination of GnRH antagonist treatments. These findings suggest that potent GnRH antagonists can effectively create a hypogonadotropic milieu without the initial enhancement of gonadotropin secretion that occurs during initiation of GnRH agonist therapy. "Medical hypophysectomy" through GnRH antagonist administration may permit a more direct and controlled approach to gonadal therapies such as ovulation induction.

Animals↗
PubMed1984

Medical hypophysectomy: II. Variability of ovarian response to gonadotropin therapy.

In an attempt to control individual variability of ovarian response to gonadotropin therapy, ovulatory monkeys received either "pure" follicle-stimulating hormone (FSH) or human menopausal gonadotropin (hMG), with or without gonadotropin-releasing hormone (GnRH) antagonist administration. Among females that responded to gonadotropin therapy, the GnRH antagonist reduced (P less than 0.05) the variability of serum estradiol patterns. Surprisingly, after pretreatment and concurrent administration of the GnRH antagonist, FSH alone was as effective as the FSH/luteinizing hormone (LH) mixture (hMG) in stimulating follicular maturation, even when serum LH levels were at or below the limits of detection. The results indicate that in a rapidly reversible hypogonadotropic state approaching a "medical hypophysectomy," concurrent gonadotropin therapy produces a less varied ovarian response. The relative (un)importance of LH in the primate ovarian cycle seems diminished in the face of evidence that FSH alone, or in the presence of vanishingly small amounts of LH, supports follicular maturation and dynamic estrogen biosynthesis.

Animals↗
PubMed1997

Increase of urocortin-like immunoreactivity in the rat hypothalamo-neurohypophysial system after salt loading and hypophysectomy.

The effect of chronic salt loading on urocortin-like immunoreactivity (Ucn-IR) was investigated in the rat hypothalamo-neurohypophysial system. In control rats a few Ucn-IR neurons were observed scattered throughout the supraoptic nucleus (SON) and few in the paraventricular nucleus (PVN). A small number of Ucn-IR fibers were observed scattered in the median eminence (ME) and the posterior pituitary. However, after 5 days of chronic administration of 2% saline, a marked increase in the number of Ucn-IR perikarya and fibers was observed in the PVN and the SON. Additionally, Ucn-IR varicosities and fibers were found in the internal zone of the ME and in the posterior pituitary. To confirm the findings and examine the possible involvement of anterior pituitary function in synthesis of Ucn, surgical hypophysectomized rats were used. Five days after hypophysectomy, a marked increase in Ucn-IR was observed in the PVN, the SON, and both the internal and the external zone of the ME. These results suggest that Ucn in the hypothalamo-neurohypophysial system may be involved in the regulation of salt balance, and possibly in the stimulation of ACTH release from the anterior pituitary.

Animals↗
PubMed1998

Effects of hypophysectomy and growth hormone administration on the mRNA levels of collagen I, III and insulin-like growth factor-I in rat skeletal muscle.

The effect of short-term treatment of normal or hypophysectomized rats with biosynthetic growth hormone (GH) was studied in extensor digitorum longus and soleus muscles. In situ hybridization revealed that in normal rats, mRNA for collagen I, collagen III and insulin-like growth factor-I (IGF-I) are expressed by fibroblasts between the muscle fibre areas and that the specificity of this location was not altered by GH administration. Hypophysectomy appeared to cause a decrease in IGF-I and decreased collagen I and III gene expression (P < 0.001, P < 0.001, respectively). GH administration seemed to increase IGF-I mRNA levels in all the animals studied. Quantitative image analysis that GH administration to hypophysectomized rats caused an increase in collagen I gene expression after 2 days (P < 0.05) and an increase in collagen III gene expression after 4 days (P < 0.05). The results indicate that the fibroblast cells are an important target for the action of GH on skeletal muscle and that the fibroblasts respond to GH by increases in the expression of mRNA for collagen I and collagen III.

Animals↗
PubMed1975

Water intoxication after hypophysectomy.

A case of excessive water retention after hypophysectomy is recorded. Its probable cause, inappropriate secretion of ADH, is explained and the diagnosis and management discussed. Three other recorded cases occurring after hypophyseal surgery are mentioned. The importance of postoperative electrolyte measurements in early diagnosis and management is emphasized.

Diuretics↗
PubMed1980

Postpartum aggression in rats: I. Effects of hypophysectomy.

For the purpose of testing the hypothesis that the high level of aggressive behavior exhibited by postparturient rats is mediated by lactogenic hormones, hypophysectomy was performed on Day 5 postpartum, and fighting against an adult male rat was measured 4 days later. Pups were exchanged daily between hypophysectomized and sham-operated or unoperated controls animals. In Experiment 1, no differences in aggressive behavior were seen between hypophysectomized, sham-hypophysectomized, and untreated lactating animals on Day 9 postpartum. In Experiment 2, the hormonal dependence of the characteristic sensitivity to the presence of the litter in the elicitation of postpartum aggression was investigated. All animals were tested three times, on Day 9, 12, and 15 postpartum; litters were removed 4 hr prior to the second aggression test. For all groups, aggression levels were high on Day 9 with the litter present, dropped on Day 12 after removal of the litter, and showed some increment or stabilization on Day 15 with the litter again present. These experiments demonstrate that neither the expression of postpartum aggression nor the sensitivity to the presence of stimuli from the litter is directly dependent upon the hormonal milieu characteristic of lactation.

Aggression↗
PubMed1971

The effect of hypophysectomy and growth hormone replacement on albumin synthesis and catabolism in the rat.

Albumin synthesis and catabolism were respectively measured by McFarlane's (1963) sodium [(14)C]carbonate method and I-labelled albumin in hypophysectomized rats, both untreated and treated with growth hormone. Hypophysectomy resulted in a decrease in both albumin synthesis and catabolic rates. These changes as shown by pair-feeding experiments could not be ascribed to decreased food intake alone. Growth hormone was shown to partially restore both albumin synthesis and catabolic rates. It is proposed that growth hormone stimulates albumin synthesis and that its effect on albumin catabolism is secondary to changes in the mass of the intravascular albumin pool.

Animals↗
PubMed1972

A decreased aminoacyl-transfer-ribonucleic acid-binding capacity of 40S ribosomal subunits resulting from hypophysectomy of the rat.

A technique that permitted the reversible dissociation of rat liver ribosomes was used to study the difference in protein-synthetic activity between liver ribosomes of normal and hypophysectomized rats. Ribosomal subunits of sedimentation coefficients 38S and 58S were produced from ferritin-free ribosomes by treatment with 0.8m-KCl at 30 degrees C. These recombined to give 76S monomers, which were as active as untreated ribosomes in incorporating phenylalanine in the presence of poly(U). Subunits from normal and hypophysectomized rats were recombined in all possible combinations and the ability of the hybrid ribosomes to catalyse polyphenylalanine synthesis was measured. The results show that the defect in ribosomes of hypophysectomized rats lies only in the small ribosomal subunit. The 40S but not the 60S subunit of rat liver ribosomes bound poly(U). The only requirement for the reaction was Mg(2+), the optimum concentration of which was 5mm. No apparent difference was seen between the poly(U)-binding abilities of 40S ribosomal subunits from normal or hypophysectomized rats. Phenylalanyl-tRNA was bound by 40S ribosomal subunits in the presence of poly(U) by either enzymic or non-enzymic reactions. Non-enzymic binding required a Mg(2+) concentration in excess of 5mm and increased linearly with increasing Mg(2+) concentrations up to 20mm. At a Mg(2+) concentration of 5mm, GTP and either a 40-70%-saturated-(NH(4))(2)SO(4) fraction of pH5.2 supernatant or partially purified aminotransferase I was necessary for binding of aminoacyl-tRNA. Hypophysectomy of rats resulted in a decreased binding of aminoacyl-tRNA by 40S ribosomal subunits.

Amino Acids↗
PubMed1976

A sex difference in hepatic glutathione S-transferase B and the effect of hypophysectomy.

The glutathione S-transferases are a group of proteins with overlapping substrate specificities and ligand-binding capacities. This report examines certain approaches to the measurement of transferase B (ligandin) in the rat liver. The ratio of catalytic activities toward 1-chloro-2,4-dinitrobenzene and 1,2-dichloro-4-nitrobenzene gives some indication of the relative proportions of the various transferases present in 100 000 g supernatants. The fraction of catalytic activity towards 1-chloro-2,4-dinitrobenzene, due to transferase B, was best measured by immunoprecipitation with anti-(transferase B). Male rat liver exhibited three times more activity towards 1,2-dichloro-4-nitrobenzene than female tissue; however, the activities towards 1-chloro-2,4-dinitrobenzene were almost identical. By assuming a specific activity of 11 mumol/min per mg, immunoprecipitable transferase B comprised 4.5 +/- 0.2% of total protein in the 100 000 g supernatant of female rat liver, and 70% of the transferase activity towards 1-chloro-2,4-dinitrobenzene. The amount of transferase B in the 100 000 g supernatant from male rat liver is significantly lower with respect to both fraction of total protein (3.3 +/- 0.2%) and overall transferase activity towards 1-chloro-2,4-dinitrobenzene (48%). Hypophysectomy eliminated this sex difference in the hepatic concentration of glutathione S-transferase B.

Animals↗
PubMed1979

Effect of hypophysectomy on liver nuclear ribonucleic acid synthesis in aging rats.

Changes in RNA synthesis in liver nuclei were observed at different ages and after hypophysectomy and hormone replacement in female Sprague-Dawley rats. As determined by the incorporation of [3H]UMP into an acid-insoluble product, RNA synthesis decreased by about 75% in intact rats from 6 months to 24 months of age. This decline with age was not observed in liver nuclei from 24-month-old rats that had been hypophysectomized at 12 months and maintained on a minimal hormone-replacement therapy. Thyroid hormones and somatotropin (growth hormone) had an additive effect on RNA synthesis in liver nuclei from these hypophysectomized rats. The same hormones had no significant effect on intact, age-matched rats. With advancing age, nuclei of intact rats had an increase in the pool of free RNA polymerase and an apparent decrease in the enzyme activity bound to nuclear chromatin. There was no change in total enzyme with age. In hypophysectomized, hormone-treated rats, free RNA polymerase activity decreased and chromatin-bound activity increased. There was no difference in total nuclear RNA polymerase activity between operated or intact rats. However, the ratio of the bound to the free activity was different. These results suggest that the ability of RNA polymerase to bind to chromatin may be involved in the age-related decrease in liver nuclear RNA synthesis of intact rats.

Aging↗
PubMed1980

Development of growth hormone receptors in rabbit and lamb liver after hypophysectomy.

The prolactin receptors of rat liver are pituitary-dependent, and previous studies have shown that prolactin itself plays a role in inducing and maintaining their presence. This study tried to determine if hepatic growth hormone (GH) receptors are comparably dependent on the pituitary. Young 47-day and older 116-day old rabbits were either hypophysectomized (H) or sham-operated (S). Hypophysectomy completely arrested the growth of the older rabbits but only reduced it by 50 p. 100 in the young ones. After 21 days, the specific binding (sb) of 125I-labelled human GH (hGH) to liver membranes was measured in H and S animals. The sb of hGH in H rabbits compared to S animals (older, young) was 14.9 p. 100 in older H rabbits and 45.5 p. 100 in young H animals. Similar studies in lambs showed that the sb of hGH in H lambs (compared to S animals) was 23.9 p. 100. When some H lambs were treated with 1 mg/kg of oGH or bGH 3 times per week, the sb of hGH was significantly increased to 56.1 p. 100 of the S levels. All changes in sb reflected changes in receptor number, as shown by the dose response binding curves. This study demonstrates that hepatic GH receptors in both the rabbit and the lamb are pituitary-dependent. The level in rabbits is correlated with the growth rate. Since GH receptor levels were partially restored in GH-treated lambs, it is possible that GH plays a role in inducing its own receptors.

Animals↗
PubMed1984

Effects of hypophysectomy and subsequent growth hormone replacement in the rat on the ability of serum to stimulate proliferation of human and mouse (BALB/c 3T3) fibroblasts.

The ability of cultured human fibroblasts to synthesize and secrete a mitogenic, somatomedin C-like peptide suggests that human fibroblasts unlike certain other cell lines may not require exogenous somatomedin for cell proliferation. The aim of this study was to examine the effects of hypophysectomy and subsequent growth hormone (GH) replacement on the ability of rat serum to stimulate proliferation and DNA synthesis in cultured human fetal skin fibroblasts. For comparison we have also examined the effects of serum from hypophysectomized (hypox) and GH-replaced hypox rats on mouse BALB/c 3T3 fibroblasts, a cell line which has been shown to require exogenous somatomedin (SM) for DNA synthesis and cell proliferation. Human fibroblast proliferation and DNA synthesis (measured as thymidine incorporation) were significantly enhanced (P less than 0.025) when these cells were cultured in low concentrations of hypox rat serum compared to normal rat serum. When thymidine incorporation into DNA was expressed in terms of a normal rat serum pool (arbitrarily assigned a potency of 1 unit/ml), serum from hypox rats was significantly more potent than serum from normal rats (1.52 +/- 0.16 (SEM) vs. 0.99 +/- 0.10 units/ml, P less than 0.0125). Replacement treatment of hypox rats with human GH, 0.2 IU/100 g body weight/day or 0.4 IU/100 g body weight/day decreased the potency of the rat serum in terms of stimulation of thymidine incorporation from 1.52 +/- 0.16 to 1.30 +/- 0.14 and 1.08 +/- 0.06 units/ml respectively. In contrast serum from untreated hypox rats was significantly less potent than normal rat serum in stimulating BALB/c 3T3 DNA synthesis (0.36 +/- 0.06 vs. 1.04 +/- 0.16 units/ml, P less than 0.0025).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Regression of myelocytic leukemia in rats after hypophysectomy.

A standard series of five intravenous injections of N-nitroso-N-methylurea (NMU) elicited selective patterns of neoplasms in male rats of the Sprague-Dawley strain; the neoplastic pattern was related to the age of the recipients. When the injections of NMU were started in weanling male rats, a specific triad of neoplasms developed that consisted of mammary carcinoma, primary myelocytic leukemia, and ear duct cancer. When the injections of NMU were started in males at age 100 days, a specific dyad of neoplastic growths was evoked that consisted of primary myelocytic leukemia and ear duct cancer, whereas mammary cancer and other neoplasms were not evident. Secondary myelocytic leukemia and myelocytic sarcoma were produced when blood from the foregoing rats with advanced primary myelocytic leukemia was injected in a subcutaneous site in newborn allogeneic rats. In a proportion of animals, primary and secondary myelocytic leukemia and myelocytic sarcoma underwent dramatic and continued regression after hypophysectomy.

Animals↗
PubMed1999

Neuromyotonia of the abducens nerve after hypophysectomy and radiation.

The clinical signs of the rarely encountered ocular neuromyotonia consist of transient involuntary tonic contraction and delayed relaxation of single or multiple extraocular muscles, resulting in episodic diplopia. With a mean time delay of 3.5 years, this motility disorder frequently follows tumor excision or adjuvant radiation near the skull base. Ocular neuromyotonia may reflect inappropriate discharge from oculomotor neurons with unstable cell membranes because of segmental demyelinization by tumor compression and radiation-induced microangiopathy. In the present paper, the authors present the case of a 53-year-old patient with a history of transsphenoidal hypophysectomy and adjuvant radiotherapy, who underwent strabismus surgery for abducens palsy.

Abducens Nerve↗