ACETYLCHOLINE STIMULATES GROWTH HORMONE SECRETION, PHOSPHATIDYL INOSITOL LABELLING, 45Ca2+ EFFLUX AND CYCLIC GMP ACCUMULATION IN BOVINE ANTERIOR PITUITARY GLANDS

in Journal of Endocrinology
Authors:
P. W. YOUNG
Search for other papers by P. W. YOUNG in
Current site
Google Scholar
PubMed
Close
,
R. J. BICKNELL
Search for other papers by R. J. BICKNELL in
Current site
Google Scholar
PubMed
Close
, and
J. G. SCHOFIELD
Search for other papers by J. G. SCHOFIELD in
Current site
Google Scholar
PubMed
Close
Restricted access
Rent on DeepDyve

Sign up for journal news

Acetylcholine (25 μmol/l) in the presence of the choline esterase inhibitor physostigmine (67 μmol/l) increased the release of growth hormone and efflux of 45Ca2+ from perifused bovine pituitary slices; the time taken for the maximal response to occur was the same. In batch incubations, acetylcholine (1 μmol/l–1 mmol/l) increased pituitary cyclic GMP concentrations in the pituitary gland within 2 min, and increased incorporation of [3H]inositol and [32P]phosphate into pituitary phosphatidyl inositol within 15 min. Cyclic AMP concentrations were not significantly changed 2 or 5 min after acetylcholine addition. All the tissue responses were inhibited by prior exposure of the tissue to atropine (1 μmol/l) but not by tubocurarine (10 μmol/l–1 mmol/l), indicating that the responses were mediated by receptors of the muscarinic type. The similarities between these responses and those to known hypothalamic hypophysiotrophic hormones are discussed.

 

  • Collapse
  • Expand