Effects of insulin on mammalian cardiac muscle

Insulin increases the contractile force of myocardium with hyperpolarization and a faster rate of fall of the action-potential plateau. This phenomenon is augmented inthe reduced-K+ or ouabain solution. It is suggested that the insulin-induced positive inotropism can be explained by facilitation of inward movement of Ca2+, which possibly is associated with an increase in outward movement of K+.