[Show abstract][Hide abstract] ABSTRACT: Total aralosides of Aralia elata (Miq) Seem (TASAES) from Chinese traditional herb Longya Aralia chinensis L was found to improve cardiac function. The present study was to determine the protective effects of TASAES on diabetic cardiomyopathy, and the possible mechanisms. Therefore, a single dose of streptozotocin was used to induce diabetes in Wister rats. Diabetic rats were immediately treated with low, medium and high doses of TASAES at 4.9, 9.8 mg/kg and 19.6 mg/kg body weight by gavage, respectively, for eight weeks. Cardiac function was evaluated by in situ hemodynamic measurements, and patch clamp for the L-type Ca2+ channel current I(Ca(2+)-L) and transient outward K+ channel current (I(to)). Histopathological changes were observed under light and electron microscope. The expression of pro-fibrotic factor, connective tissue growth factor (CTGF) was monitored using immunohistochemistry staining. Compared with diabetic group, medium and high doses, but not low dose, of TASAES showed a significant protection against diabetes-induced cardiac dysfunction, shown by increased absolute value of left ventricular systolic pressure (LVSP) and maximum rates of pressure development (+/-dp/dt(max)), and enhanced amplitude of I(Ca(2+)-L) (P<0.05). Histological staining indicated a significant inhibition of diabetes-caused pathological changes and up-regulation of CTGF expression (P< 0.05). The results suggest that TASAES prevents diabetes-induced cardiac dysfunction and pathological damage through up-regulating I(Ca(2+)-L) in cardiac cells and decreasing CTGF expression.
Full-text · Article · May 2009 · Experimental and Molecular Medicine
[Show abstract][Hide abstract] ABSTRACT: Objective: To discuss the effect of total arasolides of aralia elata (Miq) seem (TASAES) on cardiac function and protective effect on mgocardial structure in rats with early stage diabetes. Methods: The models of diabetic rats were made by an intra-abdominal injection of streptozotocin (STZ). Rats were divided into control group (C group), model group (M group) and TASAES 4.9, 9.8, 19.6 mg · kg-1 groups (T1, T2, T3 groups). At the time of 8 weeks, the hemodynamic parameters were detected in various groups; ultrastructure of cardiomyocytes was observed under electron microscope; the expression of connective tissue growth factor (CTGF) was detected by RT-PCR technique at the molecular level. Results: Compared with model group, TASAES increased the absolute value of left ventricular systolic pressure (LVSP) and ±dp/dtmax in diabetic rats, especially in high and middle dosage groups (P<0.05, P<0.01), it improved the ultrastructure of cardiomyocytes and reduced the expression of CTGF in high and middle dosage groups (P<0.01). Conclusion: TASAES can improve the cardiac function of diabetic rats in a dose dependent manner, and its protective effect may be related to the reduction of CTGF and enhancement of cardiac contractility.
No preview · Article · Mar 2008 · Journal of Jilin University Medicine Edition
[Show abstract][Hide abstract] ABSTRACT: Objective: To study the effects of exogenous phosphatidic acid (PA) on calcium current of ventricular myocytes. Methods: The Langendorff perfu sion method was used to isolate the ventricular myocytes of guinea pigs and the ventricular myocytes of guinea pigs were randomly divided into control groups, three dosage groups of PA 0.01, 0.1 and 1.0 μmol · L-1 and group of PTX 0. 1 mg · L-1 plus PA 1. 0 μmol · L-1 and group of H-7 2 μmol · L-1 plus PA 1. 0 μmol · L-1. The whole cell voltage clamp technique was used to record the calcium current of isolated ventricular myocytes of guinea pigs. Results: 0.01, 0.1 and 1.0 μmol · L-1 P A enhanced the calcium current from (288.70 ± 28.33) pA, (290.83 ± 25.12) pA and (279.54 ± 31.22) pA before administration to (304.10±28.31) pA (P>0.05), (349.80±30.13) pA (P<0.01) and (388.10±28.12) pA (P<0.001) after administration. The effects of PA on the calcium current was blocked by PTX (a G protein-coupled receptor blocking agent) and H-7 (a PKC blocking agent). Conclusion: PA can promote the opening of calcium chan nels of the ventricular myocytes by the pathway of membrane receptor-G protein-PKC in a dose-dependent manner.
No preview · Article · May 2006 · Journal of Jilin University Medicine Edition