The influence of arrhythmogenic substances on the E.C.G. of rats calcified by high doses of vitamin D2.

Calcification of the aorta and the coronary vessels as well as metastatic calcification of the heart muscle in the rat was produced by daily oral administration of 300,000 i.u. vitamin D2/kg for 6 consecutive days. E.C.G. tracings showed different pathological conditions. The response of the cardiovascular system to certain arrhythmogenic substances, e.g. aconitine and CaCl2 was generally reduced in comparison to non-treated rats.