Differences between natriuretic peptide receptors in the olfactory bulb and hypothalamus from spontaneously hypertensive and normotensive rat brain.
Natriuretic peptide receptor-A (NPR-A) functional characteristics in the hypothalamus and olfactory bulb (OB) have been investigated in spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). Autoradiographic studies demonstrate a decreased number of atrial natriuretic peptide (ANP) binding sites in the olfactory bulb and hypothalamus in SHR compared to WKY rats. We found that NPR-A showed a lower maximal binding capacity (B(max)) and higher affinity in SHR than in WKY rats both in the olfactory bulb and hypothalamus. However, despite the lower B(max) in SHR, both ANP(1-28) and ANP(5-25) stimulated similar or greater cGMP production than in WKY rats. These differences were found even before the development of hypertension. NPR-A in the olfactory bulb and hypothalamus from 3-week-old SHR showed a lower B(max) and K(d) and a higher cGMP production rate than in WKY rats, suggesting that these characteristics are intrinsic of NPR-A in SHR, instead of being a result of hypertension itself. The present study provides evidences for altered NPR-A receptor properties and function in the olfactory bulb and hypothalamus from SHR, which might be involved in the pathogenesis of hypertension.
Woodard
Geoffrey E
GE
Physiological Laboratory, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK. geoffreyw@intra.niddk.nih.gov
Zhao
Jing
J
Rosado
Juan A
JA
Brown
John
J
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology; D001345:Autoradiography; D001667:Binding, Competitive; D006152:Cyclic GMP / Q000378:metabolism; D006973:Hypertension / Q000503:physiopathology*; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism*; D009830:Olfactory Bulb / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D017461:Receptors, Atrial Natriuretic Factor / Q000378:metabolism*
C472610:atrial natriuretic peptide, rat; D009320:Atrial Natriuretic Factor; D017461:Receptors, Atrial Natriuretic Factor; D006152:Cyclic GMP