[Potential-dependent Ca2+ channels and contractile function of the heart in toxic-infectious shock caused plague].

Influence of intravenous administration to rats of murine toxin of Y. pestis (1 mg/ml, LD100) on the number of potential-operated Ca(2+)-channels, alpha- and beta-adrenergic and M1-cholinergic receptors of plasma membranes and heart contractility function has been studied in rats. The number of Ca(2+)-channels in plasma membranes and contractility of heart decreased by 50% in 1 hour after the i.v. administration of toxin and further decreased up to the lethal end. During the agonal stage of the shock desensitization of beta-adrenergic receptors has been discovered, while alpha-adrenergic and M1-cholinergic receptors remained unchanged throughout the experiments.