praeruptorin-c and Hypertrophy--Left-Ventricular

To study the intracellular free calcium ([Ca2+]i) in normal and hypertrophic left ventricular myocytes isolated from adult rat hearts and the effects of praeruptorine C (Pra-C) on them.. [Ca2+]i of single myocyte was measured with Fura 2-AM.. The resting [Ca2+]i was 87 +/- 4 nmol.L-1 in normal left ventricular myocytes, 123 +/- 7 nmol.L-1 in hypertrophied myocytes. After exposure to KCl (20, 40, and 60 mmol.L-1), the [Ca2+]i were increased by 66%, 141%, and 268% in normal myocytes, and 77%, 185%, and 243% in hypertrophic myocytes, respectively. Pra-C (1, 10, and 100 mumol.L-1) concentration-dependently inhibited the [Ca2+]i elevation caused by KCl (35 mmol.L-1) or norepinephrine (20 mumol.L-1) in both normal and hypertrophied myocytes. All of the effects of Pra-C were similar to that of nifedipine.. [Ca2+]i of hypertrophied myocytes was higher than that of normal ones and Pra-C decrease the [Ca2+]i elevation in left ventricular myocytes resulted from its calcium channel blockade.

Topics: Animals; Butyrates; Calcium; Calcium Channel Blockers; Coumarins; Drugs, Chinese Herbal; Hypertension, Renovascular; Hypertrophy, Left Ventricular; Male; Myocardium; Pyrans; Rats; Rats, Sprague-Dawley

The effects of praeruptorin C (Pra-C) on cardiac dysfunction, myocardial compliance, and collagen content in renovascular hypertensive rats have been studied. In rats with left ventricular hypertrophy (LVH), the ratio of cardiac flow (CF)/heart wet weight (HWW) and cardiac output (CO)/HWW decreased by 20.1% and 35.5%; LVSP and -dp/dtmax decreased by 19.4% and 42.1%, while LVEDP and T value were increased by 186.4% and 226%. The left ventricular diastolic pressure-volume (P-V) curve was shifted to the left and down ward compared with that of sham-operated rats. The hydroxyproline content was 5.93 +/- 0.82 mg.g-1 dry weight in the left ventricular myocardial tissue of rats with LVH which was higher than that of sham-operated rats(e.g. 4.01 +/- 0.47 mg.g-1). The content did not change in the right ventricular myocardium. After treated with Pra-C for nine weeks, the CF/HWW and CO/HWW increased by 31.3% and 25.1%, the LVSP and -dp/dtmax increased by 16.7% and 27.8%. The LVEDP and T value was reduced by 34.9% and 36.5%, respectively, compared with those of LVH. The P-V curves of these rats were shifted to the right and in the up-ward direction. The hydroxyproline content was 4.52 +/- 0.3 mg.g-1 dry weight in the left ventricular tissue. These results indicate that Pra-C improved the cardiac contractility and relaxation by increasing the coronary flow and cardiac output, and decreasing the collagen content in the ventricular myocardium.

Topics: Animals; Calcium Channel Blockers; Collagen; Coumarins; Heart Function Tests; Hydroxyproline; Hypertension, Renovascular; Hypertrophy, Left Ventricular; In Vitro Techniques; Myocardial Contraction; Myocardium; Random Allocation; Rats; Rats, Sprague-Dawley