Renal alterations of atrial natriuretic peptide receptors by
chronic moderate ethanol treatment.
Guillaume, Pascal, Than-Vinh Dam, Christina Gianoulakis, and Jolanta
Gutkowska.
Laboratory of cardiovascular biochemistry, H[circumflex]otel-Dieu
de Montr[acute]eal, H2W 1T8, Canada, and Douglas Hospital Research
Centre, McGill University, Verdun, H4E 1R3, Canada
APStracts 3:0178F, 1996.
Previous studies have shown that chronic moderate ethanol (ETOH)
consumption prevents the age-dependent increase in blood pressure.
However, the physiological systems mediating ETOH's antihypertensive
effects are not known. The objective of the present studies was to
investigate the effects of chronic (8 months) moderate ETOH
consumption on renal natriuretic receptors of hypertensive (SHR) and
normotensive (WKY) rats, using competitive binding assay and
autoradiographic techniques. In the renal glomeruli, the maximal
binding capacity (Bmax) of the heterogeneous ANP receptor population
(NPR-A and NPR-C) was significantly lower in ETOH-treated SHR and WKY
rats compared to water-treated controls. Quantification of receptor
subtypes showed that this decrease was primarily the result of NPR-C
down-regulation. The apparent dissociation constant (Kd) was also
decreased by the ETOH treatment. In the renal papilla, the Bmax of
the homogeneous receptor population (NPR-A) was significantly
elevated by long-term ETOH consumption in both strains compared to
water-treated controls. However, the Kd was unaltered by the ETOH
administration. Thus, ETOH treatment induced specific alterations in
renal natriuretic receptors which may play a role in the
"protective" effect of moderate ETOH consumption on the
age-dependent increase in blood pressure.
Received 24 April 1996; accepted in final form 18 September 1996.
APS Manuscript Number F125-6.
Article publication pending Am. J. Physiol. (Renal Fluid Electrolyte
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 5 November 1996