[Stabilizing action of verapamil "in vivo" upon the membrane of heart lysosomes (author's transl)].

The effect of the verapamil upon the stability of the membranes of lysosomes isolated from rabbit hearts was studied by means of the acid phosphatase activity, the mapping enzyme of the cytoplasmic organelles. A dose of 2.5 mg of verapamil was injected endovenously in each animal. After homogenization of a sample taken from the lower end of the heart, the lysosomes were isolated by fractionated centrifugation and refrigerated at 2 degrees C. The lysosomal activity of non treated animals was 43.1 +/- 8.9x10(-1)mU/mg. The activity of lysosomes isolated from verapamil treated animals without previous treatment "in vitro" with digitonin was 8.7 +/- 1.6x10(-1)mU/mg and the activity of those with previous treatment of digitonin was 9.1 +/- 2.1x10(-1)mU/mg. The activity of lysosomes isolated from the control group and treated "in vitro" by digitonin was 193.9 +/- 40.5x10(-10)mU/mg. Consequently, the verapamil proved to have a strong capacity of protection of the lysosome membranes when "in vivo".