[The effect of diltiazem (Lachema) on transmural non-homogeneity of histochemical changes due to the Ca-paradox].

Calcium paradox was induced by 2.5 min perfusion of the rat heart (Langedorf's system) at 37 degrees C with calcium-free Krebs--Henseleit solution and subsequent 10 min reperfusion with the same solution containing calcium. Ca2+ depletion itself did not affect the activities of the histochemically studied enzymes (succinate dehydrogenase, lactate dehydrogenase, beta-hydroxybutyric dehydrogenase, phosphorylase, and ATPases). Ca paradox was histochemically characterized by decrease and even disappearance of activities of the given enzymes and by marked transmural nonhomogeneity of these changes exhibiting a decreasing trend towards the endocardium. Diltiazem in the concentration of 0.4 and particularly of 4.0 mumol.l-1 exerted a protective effect manifested by a better preservation of the enzymatic activities.