Apelin receptor expression in ischemic and non- ischemic kidneys and cardiovascular responses to apelin in chronic two‐kidney–one‐clip hypertension in rats

Chronic kidney diseases lead to severe cardiovascular consequences such as hypertension and cardiac failure. Apelin, along with its receptor APJ have been shown to involve in cardiovascular functions including blood pressure (BP) lowering effect and also a positive inotropic effect on failing hearts. Therefore we investigated the effect of apelin on BP and cardiac contractility in chronic two-kidney–one-clip (2K1C) hypertension, a kidney disease hypertension model. The changes in the level of apelin and some other hemodynamically effective hormones in serum and apelin receptor gene expression in nonischemic and ischemic kidneys were also assessed. 2K1C was produced by placing a Plexiglas clip around the left renal artery. 16weeks later, BP and cardiac indices of contractility were measured by power lab system. The mRNA and protein level of APJ were determined by RT-PCR and Western blot methods respectively. 2K1C increased BP from 115/75mmHg in sham to 180/120mmHg in test group. Hypertensive rats had about ten times higher basal left ventricular end-diastolic pressure (LVEDP) (P