[Effects of m-nifedipine on activities of Na+,K(+)-ATPase, Ca(2+)-ATPase and Mg(2+)-ATPase in myocardium and brain of elderly renovascular hypertensive rats].
Clipping the left renal artery induced marked hypertension and hypertrophy of the left ventricle in elderly (24-month-old) rats. m-Nifedipine (m-Nif, ig 20 mg.kg-1, qd x 9 wk) significantly decreased the systolic blood pressure and the weight of the left ventricle in the renovascular hypertensive rats (RVHR). In RVHR, the activities of Na+, K(+)-ATPase and Ca(2+)-ATPase in microsomes of the myocardium and brain were reduced significantly compared with those in sham-operated rats. m-Nif was found to increase the activities of these enzymes of the myocardium and brain in elderly RVHR (P > 0.01). m-Nif 10-1000 mumol.L-1 in vitro elevated the activities of Na+, K(+)-ATPase and Ca(2+)-ATPase in the myocardium and brain of RHVR. On the contrary, the myocardial and cerebral Mg(2+)-ATPase activities were higher in RVHR than in sham-operated rats. m-Nif was shown to depress markedly this enzyme both in vivo and in vitro. These results indicate that m-Nif can improve the activities on Na+, K(+)-ATPase and Ca(2+)-ATPase in the myocardium and brain in elderly RVHR.
Xi
T
T
Department of Cardiovascular Pharmacology, Nanjing Medical University.
Rao
M R
MR
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001921:Brain / Q000201:enzymology*; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism*; D006978:Hypertension, Renovascular / Q000201:enzymology* / Q000503:physiopathology; D066298:In Vitro Techniques; D007536:Isomerism; D008297:Male; D008861:Microsomes / Q000201:enzymology; D009206:Myocardium / Q000201:enzymology*; D009543:Nifedipine / Q000494:pharmacology*; D051381:Rats; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
D017301:Ca(2+) Mg(2+)-ATPase; D000254:Sodium-Potassium-Exchanging ATPase; D009543:Nifedipine