AJP - Cell Physiology, Vol 258, Issue 1 C109-C114, Copyright © 1990 by American Physiological Society
Immunoreactive atrial natriuretic peptide in neuronal and glial cells of spontaneously hypertensive rat brain
M. K. Raizada, B. Kimura and M. I. Phillips
Department of Physiology, University of Florida, College of Medicine, Gainesville 32610.
Neuronal and glial cultures from the hypothalamic-brain stem areas of
1-day-old normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive
(SH) rat brains stained positively with atrial natriuretic peptide
(ANP)-specific antibodies. The endogenous levels of the ANP
immunoreactivity in WKY neuronal and glial cultures were 17.0 +/- 2.2 and
14.3 +/- 2.7 pg/mg, respectively. Comparable neuronal and glial cultures
from SH rat brains contained a 48 to 70% decrease in the endogenous ANP
immunoreactivity levels. Culture media from both brain cell types also
contained ANP immunoreactivity, the levels of which are significantly
higher than those found in the cells. However, similar to endogenous
levels, the media levels of immunoreactive ANP in SH neuronal and glial
cultures were significantly reduced compared with WKY brain cultures. These
observations demonstrate that endogenous ANP-like immunoreactivity is found
in neuronal and glial cells and is released into the media. The levels of
peptide are reduced in cultures of SH compared with WKY cultures,
suggesting a genetically controlled difference between the hypertensive and
normotensive rat strains long before hypertension develops.
