Haemodynamic responses to rat adrenomedullin in anaesthetized spontaneously hypertensive rats.
1. The haemodynamic effects of rat adrenomedullin (AM), a novel hypotensive peptide, were examined in anesthetized 16-18 week old spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). 2. An intravenous injection of rat AM dose-dependently reduced the mean blood pressure (MBP) with a concomitant fall in total peripheral resistance index (TPRI) and an increase in cardiac index (CI) in both strains of rats. Percent changes in MBP, TPRI and CI were not different between SHR and WKY. 3. The plasma half-life of rat AM in SHR was similar to that in WKY when it was administered at the dose of 1.0 nmol/kg. 4. These findings indicate that AM has a potent vasorelaxant activity in both SHR and WKY. The haemodynamic responsiveness to exogenous AM and its pharmacokinetics in SHR were comparable with those in WKY.
First Department of Internal Medicine, Miyazaki Medical Collge, Japan.
Y
Y
Ishiyama
K
K
Kitamura
Y
Y
Ichiki
J
J
Sakata
O
O
Kida
K
K
Kangawa
T
T
Eto
D053607:Adrenomedullin; D000595:Amino Acid Sequence; D000758:Anesthesia; D000818:Animals; D000959:Antihypertensive Agents / Q000493:pharmacokinetics / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006973:Hypertension / Q000235:genetics / Q000503:physiopathology*; D008297:Male; D008969:Molecular Sequence Data; D010455:Peptides / Q000493:pharmacokinetics / Q000494:pharmacology*; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D014655:Vascular Resistance / Q000187:drug effects
D000959:Antihypertensive Agents; D010455:Peptides; D053607:Adrenomedullin