间硝苯地平对老龄肾性高血压大鼠心肌和脑微粒体Na~＋，K~＋－ATP酶，Ca~

EFFECTS OF m-NIFEDIPINE ON ACTIVITIES OF NA+,K+-ATPase,CA2+-ATPase AND MG2+-ATPase IN MYOCARDIUM AND BRAIN OF ELDERLY RENOVASCULAR HYPERTENSIVE RATS

间硝苯地平（ｍ－Ｎｉｆ，ｉｇ２０ｍｇ·ｋｇ－１·ｄ１持续给药９周）可显著降低老龄肾性高血压大鼠（ＲＶＨＲ）血压和左室重量（Ｐ＜０．０１），增高心、脑微粒体Ｎａ＋，Ｋ＋－ＡＴＰ酶和Ｃａ２＋－ＡＴＰ酶活性（Ｐ＜０．０１），降低Ｍｇ２＋－ＡＴＰ酶活性，体外量效关系研究发现，ｍ－Ｎｉｆ在较高剂量（１０～１０００μｍｏｌ·Ｌ－１）时可增高ＲＶＨＲ心脑微粒体Ｎａ＋，Ｋ＋－ＡＴＰ酶和Ｃａ２＋－ＡＴＰ酶活性，且随剂量增加而增高。上述结果表明，ｍ－Ｎｉｆ可改善老龄ＲＶＨＲ心脑微粒体Ｎａ＋，Ｋ＋泵和Ｃａ２＋泵功能。

Clipping the left renal artery induced marked hypertension and hypertrophy of theleft ventricle in elderly(24-month-old) rats. m-Nifedipine(m-Nif,ig20mg·kg-1,qd×9wk)significantly decreased the systolic blood pressure and the weight of the left ventricle in therenovascular hypertensive rats(RVHR).In RVHR,the activities of Na+,K+-ATPase and Ca2+-ATPase in microsomes of themyocardium and brain Were reduced significantly compared with those in sham-operated rats.m- Nifwas found to increase the activities of these enzymes of the myocardium and brain in elderly RVHR(P>0.01).m-Nif 10～1000μmol·L-1 in vitro elevated the activities of NaK+-ATPase andCa2+-ATPase in the myocadium and brain of RHVR.On the contrary,the myocardial and cerebral Mg2+-ATPase activities were higher in RVHR than in sham-operated rats.m-Nif was shown todepress markedly this enzyme both in vivo and in vitro.These results indicate that m-Nif can improvethe activities on Na+,K+-ATPase and Ca2+-ATPase in the myocardium and brain in elderly RVHR.