AJP - Regulatory, Integrative and Comparative Physiology, Vol 268, Issue 1 192-R200, Copyright © 1995 by American Physiological Society
Regulation of NPY/NPY Y1 receptor/G protein system in rat brain cortex
M. C. Michel, K. Lewejohann, W. Farke, A. Bischoff, F. Feth and W. Rascher
Department of Medicine, University of Essen, Germany.
Neuropeptide Y (NPY) content, NPY receptors, and alpha-subunits of the G
proteins Go and Gi were determined in cerebral cortex of male normotensive
Wistar-Kyoto and spontaneously hypertensive rats at 3-28 wk of age and of
adult female rats. NPY lacked major effects on adenylate cyclase or
inositol phosphate formation. NPY content was similar in all normotensive
groups but lower in spontaneously hypertensive rats at all ages. 125I-NPY
labeled a homogeneous population of Y1-like receptors. The Y1 NPY receptor
number gradually increased with age with similar values in both strains but
was significantly smaller in female than in male rats. The Y1 NPY receptor
affinity was similar in all male groups but greater in female rats. The
abundance of immunodetectable Go alpha and Gi alpha and of pertussis toxin
substrates was less at 3 wk than in older rats but similar in both sexes
and strains. We conclude that rat cerebral cortex contains Y1-like
receptors; sex, age, and blood pressure differentially regulate NPY
content, Y1 NPY receptors, and Go alpha and Gi alpha.
