Effect of low concentrations of strophanthidin on isolated guinea pig failure hearts / 中国药理学通报

AIM To study the effects of strophanthidin (Str) on cardiac function and Na +,K +-ATPase activity in isolated guinea pig heart failure model. METHODS Langendorff isolated heart failure models made by perfusing heart with K-H solution containing sodium pentobarbital. Eight-channel physiological recording instrument was used to determine cardiac function. Colorimetry method was used to determine cardiac sarcolemmal Na +,K +-ATPase activity. RESULTS Str increased the heart rate, left ventricular systolic pressure and the maximum rise or decline rate of left ventricular pressure in a concentration-dependent manner at 1?10 -9～1?10 -7 mol?L -1. But Str caused first a rise, then a reduction of contractility and arrhythmia accompanied by inhibition of Na +,K +-ATPase when the concentration of Str was higher than 1?10 -6 mol?L -1. Str had no obvious effect on Na +,K +-ATPase activity at 1?10 -7 mol?L -1, but increased cardiac activity at 1?10 -10～1?10 -8 mol?L -1. CONCLUSION The inotropic effect and heart toxicity of Str at higher concentration is due to inhibition of Na +,K +-ATPase, but the inotropic effect of Str at lower concentration is not the result of inhibition of Na +,K +-ATPase activity.

EFFECT OF Se ON Na~+ ,K~+-ATPase AND 5'-NUCLEOTIDASE ACTIVITIES OF CARDIAC SARCOLEMMA IN RATS / 西安交通大学学报(医学版)

Sprague—dawey rats were fed for one to three months with Se—deficient grains from Keshan disease area, Se—supplemented diet and stock diet,respectively. Changes of Na~+ ,K~+ ATPase and 5'—nucleotidase activities in cardiac sarcolemma ,Se Contents in liver and plasma and GSH—px activities in Liver and red blood cells of rats were observed. The results showed that Na~+ ,K~+—ATPase. and 5'—nucleotidase activities in cardiac sarcolemma in Se-deficient group rats were significantly decreased,hepatic and plasma Se contents as well as hepatic and erythrocyte GSH—px activities were also significantly decreased at of feeding 30,60 and 90 d as compared to Se—supplemented or stock diet group. There was no significant difference in these parameters between Se—supplemented or stock diet groups There was no significant difference in these paramefers between Se—supplemented and stock diet groups。