[Effects of antibodies on contractility of papillary muscle in the rat heart and duration of descending phase of action potential plateau under influence of exogenic arachidonic acid and inhibiting its metabolism].

The effects of both arachidonic acid (AA) and inhibition of its metabolism on the antibody-induced changes in the mechanical contraction and action potentials of the isolated papillary muscles were studied. It has been shown that antibody-dependent induction of AA oxidation led to the initiation of Ca2+ entry through voltage-dependent Ca2+ channels of a myocyte. Inhibition of the lipoxygenase way of AA peroxidation prevented Ca2+ overload of cardiomyocytes more than inhibition of the cyclooxygenase way, but less than blocking Ca2+ channels.