title: Atrial natriuretic peptide and the natriuresis due to acute beta-blockade in conscious hypertensive rats.
abstract: Acute beta-adrenoceptor blockade in rats is known to produce a natriuresis of hitherto uncertain cause. To investigate this phenomenon plasma atrial natriuretic peptide (ANP) concentrations were measured in groups of conscious metoprolol-treated and control rats. In the active treatment group the blood pressure decreased slowly, as expected, settling at a lower level after 2 hours, and the mean sodium excretion doubled 1 hour after metoprolol administration. This natriuretic effect was maximal after 40-60 minutes and thereafter slowly declined towards basal values. The period of enhanced sodium excretion was associated with a significant rise (68%) of the mean ANP plasma concentration. It suggested that this increase in plasma ANP concentration can mediate the acute natriuretic effect beta-adrenoceptor blockade.
mesh_terms: D000818:Animals; D009320:Atrial Natriuretic Factor / Q000097:blood* / Q000378:metabolism; D006973:Hypertension / Q000188:drug therapy / Q000503:physiopathology*; D008297:Male; D008790:Metoprolol / Q000494:pharmacology; D009318:Natriuresis / Q000187:drug effects; D051381:Rats; D011918:Rats, Inbred SHR; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000502:physiology*; D012964:Sodium / Q000652:urine
chemical_list: D011943:Receptors, Adrenergic, beta; D009320:Atrial Natriuretic Factor; D012964:Sodium; D008790:Metoprolol