[The effect of calcium antagonist nitrendipine on the morphological picture of experimentally-produced myocardial injuries in rats].

Abstract

Malignant renal hypertension was induced to Wistar rats by means of two methods (Lörincz-Gorácz and Rojo-Ortega-Genest procedures), and hypoxaemia was produced by application of two ligatures to an aortic segment, for two hours. The lesions caused by these experimentally established pathological conditions were analysed by the following criteria, after treatment with a Ca-blocking agent (Nitrendipine, Bayer, Leverkusen): Changes in systematic blood pressure; Histochemical detectability of myocardial and vascular lesions as a consequence of artificially induced hypertension and hypoxaemia; Assessment by means of the tracer technique (Ferrlecit, Nattermann, Cologne) of alterations to vascular permeability in small cardiac vessels of rats treated and not treated with the Ca-blocking agent; Detection of lesions in small vessels of other organs, such as intestine, mesentery, and pancreas, in rats treated and not treated with the Ca-blocking agent. This study has been conducted for the purpose of elucidating vascular lesions resulting from lasting hypertension and short-term hypoxaemia, with particular attention being given to effects of therapeutic intervention on morphological expression of vascular damage. The Ca-blocking agent had a favourable effect on vascular alterations due to long-term and short-term injuries, since the animals treated with Nitrendipine exhibited drop in blood pressure and developed very mild vascular lesions, if any. The cardioprotective action of Nitrendipine was readily obvious under the above experimental conditions.