Gene expression of natriuretic peptide receptors in rats with DOCA-salt hypertension.
In our previous studies, we found that the atrial natriuretic peptide (ANP) binding and guanylyl cyclase activity of A-type natriuretic peptide receptors (NPR-A) were upregulated in renal papillae but downregulated in vascular tissues and glomeruli of rats with deoxycorticosterone acetate (DOCA)-salt hypertension [E. Nuglozeh, G. Gauquelin, R. Garcia, J. Tremblay, and E. L. Schiffrin. Am. J. Physiol. 259 (Renal Fluid Electrolyte Physiol. 28): F130-F137, 1990]. To further understand the molecular significance of these regulations, we measured the relative abundance of the transcripts of NPR-A and NPR-B by Northern blot in the aorta, mesenteric arteries, adrenal cortex, renal papillae, and lungs in DOCA-salt hypertensive and control rats. In renal papillae we also examined the translation and transcription of NPR-A by ribosome loading and run-on assay. Compared with controls, the steady-state levels of mRNA for NPR-A were increased in the aorta and mesenteric arteries but were decreased in the adrenal cortex and renal papillae in DOCA-salt-treated rats. NPR-B mRNA was decreased in the aorta, mesenteric arteries, and adrenal cortex in hypertensive rats. In lungs the mRNA for both receptors was unchanged. Translation of NPR-A mRNA, as assessed by ribosome loading, was reduced in renal papillae. Transcriptional activity of its gene was not detectable in these tissues. Guanosine 3',5'-cyclic monophosphate levels generated by NPR-A in renal papillae and by NPR-A and NPR-B in the adrenal cortex, aorta, and mesenteric arteries of DOCA-salt-treated rats remained increased in hypertension. The higher NPR-A activity in the presence of a lower level of its mRNA in renal papillae and the higher NPR-B activity in the presence of a lower level of its mRNA in the vasculature, adrenal cortex, and lungs can alternatively be explained by receptor stabilization or increased receptor recycling.
Nuglozeh
E
E
Department of Medicine, Hôpital St.-Luc, Université de Montréal, Quebec, Canada.
Mbikay
M
M
Stewart
D J
DJ
Legault
L
L
D000302:Adrenal Cortex / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000378:metabolism; D009320:Atrial Natriuretic Factor / Q000494:pharmacology; D006152:Cyclic GMP / Q000378:metabolism; D003900:Desoxycorticosterone; D005786:Gene Expression Regulation; D006973:Hypertension / Q000139:chemically induced / Q000378:metabolism*; D007668:Kidney / Q000187:drug effects / Q000378:metabolism; D008168:Lung / Q000378:metabolism; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects / Q000378:metabolism; D009928:Organ Specificity; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D017461:Receptors, Atrial Natriuretic Factor / Q000096:biosynthesis*; D012270:Ribosomes / Q000378:metabolism; D012982:Sodium, Dietary; D014158:Transcription, Genetic
D012333:RNA, Messenger; D012982:Sodium, Dietary; D003900:Desoxycorticosterone; D009320:Atrial Natriuretic Factor; D017461:Receptors, Atrial Natriuretic Factor; D006152:Cyclic GMP