IN-VITRO STEROIDOGENIC EFFECTS OF NEUROPEPTIDE-Y (NPY1-36), Y-1 AND Y-2 RECEPTOR AGONISTS (LEU(31)-PRO(34) NPY, NPY18-36) AND PEPTIDE YY (PYY) ON RAT ADRENAL CAPSULE ZONA GLOMERULOSA

The effects of neuropeptide Y (NPY1-36), of two analogs (Leu(31)-Pro(3 4) NPY and NPY18-36) and of Peptide YY (PW) on aldosterone and cortico sterone secretions by freshly isolated rat adrenal capsule/zona glomer ulosa preparations were investigated in vitro. NPY-related peptides (N PY1-36, Leu(31)-Pro(34) NPY, NPY18-36), but not PW, induced a dosedepe ndent release of aldosterone at concentrations ranging from 10(-8) to 10(-6) M. All the investigated peptides failed to significantly affect corticosterone secretion in concentrations ranging from 10(-10) to 10 (-6) M (NPY1-36, NPY18-36), 10(-11) to 10(-6) M (Leu(31)-Pro(34) NPY) or 10(-9) to 10(-6) M (PYY). Aldosterone secretion by this preparation of isolated adrenal capsule/zona glomerulosa was also significantly s timulated by high potassium levels (55 mEq) or by angiotensin II (A(II )) in concentrations ranging from 10(-8) to 10(-6) M. Moreover, NPY an d Y, or Y, receptor agonists were positive aldosterone releasing agent s as potent as A(II). The present data support the existence of: (1) N PY binding sites of the YS-like subtype, on rat adrenal capsule/zona g lomerulosa. (2) A stimulatory effect of NPY on aldosterone production. So that the NPY ergic innervation of the rat adrenal capsule/zona glo merulosa could be implicated in the multifactorial control of aldoster one production.