[Changes of vasoactive substances in myocardium of chronic renal ischemia rats]

To investigate the relationship between the vasoactive substances including endothelin-1 (ET-1), calcitonin gene-related peptide (CGRP), and nitric oxide (NO) in myocardium and the cardiac functions in chronic renal ischemia rats.

Male Wistar rats weighting 180-200 g were randomly divided into 2 groups: operation group (n=30) and sham operation group (n=10). A ligation of abdominal aorta between right and left renal artery was made by silk suture in operation group and the necrosis degree of aorta was about 50%. Aorta was not ligated in sham operation group. Sixteen weeks after operation, invasive measurement of blood pressure and cardiac function were performed, and content of ET-1, CGRP, and NO in myocardium were determined.

Compared with sham operation group, blood pressure significantly increased in the operation group after ligation, along with decreased cardiac systolic and diastolic function, increased left ventricular mass index. After 16 weeks, compared with sham operation group, the content of ET-1 in cardiac tissue were significantly elevated in operation group [(361.0+/-118.7) vs. (503.4+/-139.6 ) pg/ml, P<0.01), along with significantly decreased CGRP content [(74.4+/-24.8) vs. (45.4+/-15.1) pg/ml, P<0.01). The content of ET-1 in cardiac tissue was negatively correlated with the maximum pressure rise rate of left ventricular r=-0.37, P<0.05).

Chronic kidney ischemia caused by abdominal aorta ligation may result in the increase of ET-1 content in cardiac tissue and decrease of CGRP decreased. The content of ET-1 in cardiac tissue is also negatively correlated with left ventricular systolic function.