EFFECT OF LEIURUS-QUINQUESTRIATUS HEBREUS VENOM ON CALCIUM AND DEOXYGLUCOSE UPTAKE IN CULTURED CARDIAC-CELLS

The effects of scorpion venom Leiurus quinquestriatus hebreus were stu died on cardiac cells grown in culture. The venom (30 mu g/ml) increas ed significantly (P < 0.05) Ca2+ uptake into intact cardiocytes and to sarcoplasmic reticulum of skinned cells. [H-3]Deoxyglucose uptake was also increased significantly (P < 0.05) in venom treated cardiocytes. It was found that fractions I and III of the venom, separated by gel filtration and ion exchange chromatography, are responsible for the in creased Ca2+ uptake by the sarcoplasmic reticulum, whereas fraction II b, III and IV are responsible for the accelerated rate of uptake of Ca -45 and [H-3]deoxyglucose by intact cells. Ca channel blockers prevent ed these effects and similar results were obtained by propranolol. Thu s, it is concluded that the venom exerts its effect through activation of beta-adrenoceptors which causes the opening of L-type Ca channels. (C) 1996 Elsevier Science Ltd.