Mechanism of inhibition of renin release by clonidine in rats.
In anaesthetized rats, the intracisternal injection of clonidine (1 microgram/kg) reduced mean arterial pressure (MAP), increased plasma renin concentration (PRC) while naphazoline (5 microgram/kg) was ineffective. The i.v. administration of clonidine (30 microgram/kg) still lowered MAP, but in this case, the drug decrease PRC, naphazoline (45 microgram/kg, i.v.) also reduced PRC. It is suggested that i.v. clonidine and naphazoline reduce renin release through activation of alpha-adrenoceptors within the kidney.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002946:Cisterna Magna; D003000:Clonidine / Q000494:pharmacology*; D007275:Injections, Intravenous; D008297:Male; D009278:Naphazoline / Q000494:pharmacology; D051381:Rats; D012083:Renin / Q000097:blood / Q000378:metabolism*
D012083:Renin; D009278:Naphazoline; D003000:Clonidine