Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P61278 (somatostatin)
 22,083 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Intrahypothalamic somatostatin-containing neurons were investigated immunohistochemically. In intact rats, immunoreactive cell bodies appeared in the rostral periventricular area, and immunoreactive beaded fibers were observed to terminate in the median eminence and to form delicate networks surrounding immunonegative cell bodies within the medial preoptic, suprachiasmatic, arcuate, ventromedial and premammillary nuclei. Intraventricular colchicine infusion resulted in the appearance of immunoreactive cell bodies in the arcuate, ventromedial and suprachiasmatic nuclei, and an increase in the number of cell bodies seen in the periventricular area. Complete deafferentation of the medial-basal hypothalamus excluding the rostral periventricular area caused the immunoreactive structures in the median eminence to disappear and enhanced the staining of periventricular cell bodies. In the arcuate and ventromedial nuclei, the immunoreactive fiber networks were left intact and the immunoreactive cell bodies were occasionally recognized. Horizontal knife cut between the arcuate nuclei and median eminence did not alter immunoreactivity in either region. Neonatal administration of MSG caused only the disappearance of arcuate nuclei. The results indicate that two kinds of somatostatin neuronal systems exist in rat hypothalamus: one is involved in the production of hormonal somatostatin and the other serves for the regulation of neuronal activities in restricted hypothalamic nuclei.
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PMID:Immunohistochemical studies of intrahypothalamic somatostatin-containing neurons in rat. 612 47

This study was designed to further investigate our postulate regarding the inhibitory role played by central alpha 2-adrenergic pathways on hypothalamic somatostatin (SS) release in rats. The growth hormone (GH) responses to exogenous GH-releasing factor (GRF; 3 micrograms/kg i.v.) or clonidine (CLO; 100 micrograms/kg i.v.), either given alone or in combination, were tested in 3-month-old male rats made GH-releasing hormone (GH-RH) deficient neonatally by administration of monosodium glutamate (MSG; 4 mg/g body weight s.c.). To prevent the presumable decrease in the pituitary GH content in these animals from leading to an erroneous interpretation of the results obtained, half of these rats were given GRF (MSG-GRF rats; 30 micrograms/kg s.c.) for 3 days immediately prior to GH testing. The other half of MSG-treated and non MSG-treated rats received saline during these days (MSG-S and controls, respectively). To establish the efficiency of GRF priming, the pituitary GH content was measured in other MSG-GRF, MSG-S, and control animals. The mean (+/- SEM) GH peaks in response to GRF challenge were significantly higher in controls than in MSG-GRF rats (125.2 +/- 28.5 vs. 67.5 +/- 19.4 micrograms/l; p < 0.05), while no significant GRF-induced GH release was observed in the MSG-S group. Most likely these results are related to the different pituitary GH content, significantly (p < 0.01) higher in controls than in MSG-GRF rats, and in the latter higher than in MSG-S animals (p < 0.05). CLO administration did not evoke a significant GH release in MSG rats, whether primed with GRF or not.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Clonidine potentiates the growth hormone response to a growth hormone releasing hormone challenge in hypothalamic growth hormone releasing hormone deficient rats. 761 33

Monosodium glutamate (MSG), administered to newborn rats produces extensive lesions in neurons of the arcuate nuclei of the hypothalamus. The cells represent the site of neurohormone production, including the production of both growth-hormone releasing hormone (GHRH) and somatostatin. Studies were performed on male Wistar strain rats, subcutaneously injected with MSG, at 4 mg/g body weight, on days 2, 4, 6, 8 and 10 of life. When the rats reached the age of 18 months, they were additionally stimulated with a single dose of TSH (Ambinon). When the rats reached the age of 6, 12, or 18 months, their thyroids were isolated and fixed in Bouin's solution. In HE-stained preparations, planimetric and volumetric proportions occupied by the epithelial fraction, colloid and stroma, the number of thyroid follicles per mm2 and the thickness of epithelium were determined. Serum T3 and T4 levels were quantified by RIA. Significance of differences was tested using Student's t test. The weight of experimental rat thyroids showed no significant variations as compared to the controls but were greatest in the group of 12-month-old rats. The same was noted for the volumetric fractions of epithelium, colloid and stroma. The planimetric fractions occupied by epithelium, colloid and stroma in the thyroid remained unchanged and amounted to 60%, 31% and 9%, respectively. The number of follicles per mm2 thyroid cross-section in the MSG-treated 6-, 12- or 18-month-old rats was 131.3, 116.2 and 130.4, respectively, and did not differ from control values. Thickness of follicular epithelium showed no significant variations. Serum T3 levels in the rats examined after 6, 12 or 18 months were increased by 67%, 89% and 33%, respectively, as compared to serum T4 levels. When compared to the controls, the serum T4 level was lower only in the 12-month-old MSG-treated rats and the serum T3 level was higher in 18-month-old MSG-treated rats. The ability of the thyroid to respond to Ambinon stimulation was preserved. The results of our investigations suggest that the rat hypothalamic centers involved in regulation of the pituitary-thyroid axis are slightly affected by neonatal administration of MSG.
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PMID:Effect of neonatal treatment with MSG (monosodium glutamate) on thyroid of the adult male rats. 998 51

Biometric parameters, glycemia and activity levels of plasma neutral aminopeptidase (APN) and dipeptidyl peptidase IV (DPPIV) were measured in monosodium glutamate obese and food-deprived rats (MSG-FD), to analyze the involvement of these enzymes in such situations. Plasma APN was distinguished as sensitive (PSA) (K(m) = 7.8 x 10(-5) mol/l) and predominantly insensitive (APM) (K(m) = 21.6 x 10(-5) mol/l) to puromycin, whereas DPPIV was sensitive (DPPIV-DS) (K(m) = 0.24 x 10(-5) mol/l) and predominantly insensitive (DPPIV-DI) (K(m) = 7.04 x 10(-5) mol/l) to diprotin A. Although unchanged in the MSG and food-deprived animals, APM activity levels were closely correlated with body mass, Lee index, and mass of retroperitoneal fat pad in the food deprived, but not in the MSG animals. DPPIV-DI activity levels decreased by 33% and were correlated with body mass, Lee index, and mass of periepididymal fat pad in the food-deprived MSG rats. These data suggest that APM and DPPIV-DI are respectively related to the downregulation of somatostatin in food-deprived rats, and to the recovery of energy balance in MSG obese rats during food deprivation.
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PMID:Neutral aminopeptidase and dipeptidyl peptidase IV activities in plasma of monosodium glutamate obese and food-deprived rats. 1987 9