Ventricular myosin and creatine-kinase isoenzymes in hypertensive rats treated with captopril.
In the myocardium, myosin and creatine kinase isoforms possess different capacities for using O2 and energy-rich phosphates. We studied electrophoretically the distribution of these isoforms in 19 hypertensive rats (two-kidney, one clip model of hypertension) and in age-matched controls. After 6 weeks of hypertension, seven rats were treated with captopril (2 mg/kg daily) for 4 weeks, six were left hypertensive for another 4 weeks, and the remaining rats were killed under ether anesthesia. In the latter, ventricular mass was significantly higher than in controls; V3 isomyosin was 32.3 +/- 6.8% versus 0%, and both creatine kinase-MB and -BB were increased at the expense of creatine kinase-MM (creatine kinase-MB = 29 +/- 2.8% vs. 14.7 +/- 1.8%, p less than 0.001; creatine kinase-BB = 3.1 +/- 0.6% vs. 1.7 +/- 0.8%, p less than 0.001). After 10 weeks of hypertension, ventricular mass, V3 isomyosin, and both creatine kinase-MB and -BB isoforms were found to be persistently higher than in controls. At the same time, captopril-treated rats showed reduced but not normalized blood pressure levels, normalized ventricular mass, and prevalence of the V1 isomyosin (56.9 +/- 22% vs. 47.9 +/- 23.8% in normotensive controls, p = NS). However, higher levels of creatine kinase-MB and -BB were still found in these rats in comparison with the normotensive controls (creatine kinase-MB = 22.4 +/- 5.4% vs. 15.8 +/- 2.8%, p less than 0.025; creatine kinase-BB = 2.3 +/- 0.1% vs. 1.8 +/- 0.3%, p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)
Pauletto
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P
Institute of Clinica Medica I, University of Padova, Italy.
Nascimben
L
L
Piccolo
D
D
Secchiero
S
S
Vescovo
G
G
Scannapieco
G
G
Dalla Libera
L
L
Carraro
U
U
Pessina
A C
AC
Dal Palù
C
C
D000818:Animals; D002216:Captopril / Q000494:pharmacology*; D003402:Creatine Kinase / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D006352:Heart Ventricles; D006978:Hypertension, Renovascular / Q000201:enzymology*; D007527:Isoenzymes / Q000378:metabolism; D009206:Myocardium / Q000201:enzymology*; D009218:Myosins / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D007527:Isoenzymes; D002216:Captopril; D003402:Creatine Kinase; D009218:Myosins