Enhanced dilatation by atrial natriuretic peptide of renal arcuate arteries from young, but not adult, spontaneously hypertensive rats.
The effects of a synthetic atrial natriuretic peptide (sANP) on the contractile response of isolated renal resistance vessels (internal diameter 180-300 micron) from young (5 wk) and adult (20 wk) spontaneously hypertensive (SHR) and control Wistar-Kyoto (WKY) rats have been examined. Segments of the vessels were mounted as ring preparations on an isometric myograph and a sub-maximal tone was induced with potassium chloride. All vessels relaxed in a concentration dependent manner when sANP was added to the chamber solution; the threshold concentration was 10(-10) mol/L, but half-maximal relaxation was seen at about 10(-8) mol/L. The vessels from the young SHRs relaxed slightly more than those from the young WKYs. There was no difference in the relaxation of the vessels from the adult SHRs and WKYs. The results suggest that although slight differences in sensitivity to atrial natriuretic peptide may exist in young SHRs, the greater hypotensive action of infused atrial natriuretic peptide which has been reported for adult SHRs is not related to a greater relaxing effect of the peptide on the renal resistance vessels.
D000367:Age Factors; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D006973:Hypertension / Q000503:physiopathology*; D066298:In Vitro Techniques; D008297:Male; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D012077:Renal Artery / Q000187:drug effects* / Q000503:physiopathology; D014664:Vasodilation / Q000187:drug effects*
D009320:Atrial Natriuretic Factor