We report the first demonstration of an Aldosterone Secretion Inhibitory Factor (ASIF) in acid extracts of bovine adrenal medulla. Following separation from catecholamines and enkephalins, this factor leads to an 80% inhibition of PGE1-stimulated secretion of aldosterone from bovine adrenal zona glomerulosa. ASIF is retained on cation exchange gels and behaves as a small 5K-dalton peptide on Sephadex G-50. This factor cross-reacts in a radio-receptor assay for [125I] atrial natriuretic factor (ANF). ASIF is distinct from all neuropeptides formerly detected in the adrenal medulla, e.g. somatostatin, enkephalin, neuropeptide Y, dynorphin, neurotensin. In the adrenal gland, this ANF-like factor is predominantly found in the medulla (4 pmo1/mg protein), with only trace amounts in the cortex (0.1 pmo1/mg protein). ASIF might perhaps correspond to the endogenous ligand for the receptor sites that we have previously identified with [125I]ANF in bovine adrenal cortex and could contribute to the formerly reported attenuating influence of the adrenal medulla on mineralocorticoid production.
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Pharmacology, Toxicology and Pharmaceutics(all)