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Modulation of growth hormone (GH) secretion and GH mRNA levels by GH-releasing factor, somatostatin and secretagogues in cultured bovine adenohypophysial cells.
- Source :
-
The Journal of endocrinology [J Endocrinol] 1990 Apr; Vol. 125 (1), pp. 109-15. - Publication Year :
- 1990
-
Abstract
- The effects of endogenous hypothalamic neurohormones and activators of second messenger signalling systems on the secretion of GH and on cell content of GH mRNA of cultured bovine adenohypophysial cells were studied. Synthetic bovine GH-releasing factor (bGRF; 100 nmol/l) increased secretion of GH by bovine adenohypophysial cells five-fold relative to control. Forskolin (an adenyl cyclase activator; 10 mumol/l) and the synthetic cyclic AMP analogue dibutyryl cyclic AMP (dbcAMP; 1 mmol/l) increased secretion of GH by 1.9- and 1.7-fold respectively, relative to control. The protein kinase C activator phorbol 12-myristate 13-acetate (PMA), provided at 1 mumol/l or 10 nmol/l, increased GH secretion by 6.6- and four-fold respectively, relative to control. Somatostatin-14 (SRIF-14) attenuated basal, bGRF-, forskolin- and dbcAMP-stimulated secretion of GH by 40, 49, 47 and 67% respectively, but did not, however, diminish PMA-stimulated GH secretion. The content of GH mRNA in cultured bovine adenohypophysial cells increased 2.2-, 1.7- and 3.2-fold by administration of bGRF, forskolin and PMA respectively, relative to control. Although GH mRNA content was unchanged by SRIF-14 treatment relative to control, SRIF-14 did reduce bGRF-stimulated bGH mRNA content by 67%. This study demonstrates that mechanisms subserving GH secretion in bovine adenohypophysial cells (e.g. adenyl cyclase and protein kinase C) may be coupled with mechanisms which regulate expression of the GH gene or with factors affecting message stability.
- Subjects :
- Animals
Bucladesine pharmacology
Cattle
Cells, Cultured
Colforsin pharmacology
Pituitary Gland, Anterior cytology
Pituitary Gland, Anterior drug effects
Tetradecanoylphorbol Acetate pharmacology
Growth Hormone metabolism
Growth Hormone-Releasing Hormone pharmacology
Pituitary Gland, Anterior metabolism
RNA, Messenger metabolism
Somatostatin pharmacology
Subjects
Details
- Language :
- English
- ISSN :
- 0022-0795
- Volume :
- 125
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- The Journal of endocrinology
- Publication Type :
- Academic Journal
- Accession number :
- 1971002
- Full Text :
- https://doi.org/10.1677/joe.0.1250109