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Regulation of growth hormone release: evidence against negative feedback in rat pituitary cells

, : Regulation of growth hormone release: evidence against negative feedback in rat pituitary cells. Endocrinology 108(6): 2287-2292

To determine if the anterior pituitary gland is the site of negative feedback inhibition of GH [growth hormone] release, the effect of GH and multiplication-stimulating activity (MSA), a member of the somatomedin family, on isolated rat anterior pituitary cells in primary culture was studied. The effect of GH was examined in 2 ways: by adding to the cultures human GH (10-20 .mu.g/ml) which was biologically active in the rat, but not cross-reactive in the rat GH (rGH) radioimmunoassay and by comparing rGH secretion in cultures of different cell densities. No suppression of either basal or prostaglandin[PG]E1-stimulated rGH release was found. An enhancement observed in serum-free conditions at high human GH concentrations was interpreted as a nonspecific response to protein, because bovine serum albumin produced the same effect. When added in the presence of serum, MSA (1-500 ng/ml) had no effect on rGH secretion. In the absence of serum, there were 71 and 30% increases in the basal and PGE1-stimulated rates of hormone release, respectively, possibly attributable to a trophic effect of MSA. Five other hormones [epidermal growth factor, nerve growth factor, placental lactogen, prolactin, and proinsulin] having structural or functional similarity to either GH or somatomedin also failed to inhibit rGH secretion. These results do not support the hypothesis that GH or somatomedin exerts a negative feedback effect on GH release directly on the anterior pituitary gland. Most likely, the hypothalamus or a higher brain center is the site for such regulation.

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Accession: 006288295

PMID: 6112137

DOI: 10.1210/endo-108-6-2287

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Keenan, P. E., 1994: The coral-roots. Six Corallorrhiza (coral-root) species are native to N. America. The flowers of C. striata, C. maculata, C. trifida, C. odontorhiza, C. wisteriana, C. mertensiana and various colour forms and varieties are described. Species distribution and habit...

Hanson, K. P.; Komar, V. E., 1978: Possibility of repair of the structural lesions in the mitochondrial dna from x irradiated mammalian cells/. In mitochondria of eukaryotic cells some kinds of structural DNA damage can be repaired. In particular, the existence of an enzymatic system of rejoining single-stranded breaks induced by X-irradiation may be experimentally grounded.

Kullmann J.; Reuther C. D.; Schoenenberg R., 1977: Transition from the geosynclinal stage to orogenesis in the Variscan formation of the Cantabrian Mountains. Breviora Geologica Asturica 21(1): 4-11

Ingles M.; Anadon P., 1991: Relationship of clay minerals to depositional environment in the non-marine Eocene Pontils Group, SE Ebro Basin (Spain). The Eocene sequence along the central part of the SE margin of the Tertiary Ebro Basin (Igualada area) consists of alternating marine and non-marine deposits up to 2000 m thick. Non-marine conditions persisted through the Cuisian-early Bartonian (...

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