The actions of insulin on cardiac contractility

Cellular Mechanisms Responsible for the Inotropic Action of Insulin on Failing Human Myocardium

“…Some commercial insulin preparations contain phenol or mcresol (3 methyl-phenol) as a preservative, which exerts a negative inotropic effect, and this may affect the experimental results. 9,10,29,30 Similar to previous studies, 5,6,8,10 we have shown that the positive inotropic effect of insulin was partially preserved in the absence of glucose, suggesting that its effects in the failing human myocardium are not entirely related to its ability to facilitate transport of glucose across the myocardial cell and that the hormone may affect other mechanisms that alter myocardial contractility. The results of the present study do not rule out an important role of insulin upon glucose transport, but suggest that a second mechanism, independent from metabolic factors, might play a significant role in the hormone's inotropic action.…”

The effect of insulin and glucagon on systolic properties of the normal and septic isolated rat heart

“…There, too, the information in the literature is contradictory. While Farah and Turtle (3,4) observed no cardiac effects of glucagon on the intact dog heart but noted an increase in cardiac output and decrease in right atrial pressure in the isolated heart-lung preparation, Glick et al (8) produced marked increases in maximal developed tension by adding glucagon both to the intact dog heart as well as to the cat papillary muscle. Kruty et al (11) found glucagon to have only a short-lasting positive inotropic effect coupled with enhancement of oxidative processes in the myocardium at mitochondrial level.…”

“…Insulin was also found to augment myocardial contractility in the normal newborn piglet heart (15), rat heart under conditions of normal perfusion (4,19), and increased pressure and volume workload (15). Archer et al (1) in a canine endotoxin shock model were able to reverse, by the infusion of massive doses of insulin, all signs of myocardial dysfunction, advocating the clinical use of glucose-insulin-potassium.…”

Severe Amlodipine Intoxication Treated by Hyperinsulinemia Euglycemia Therapy

“…Increasing amounts of data from studies in animals and humans support the administration of insulin while maintaining normal blood glucose levels (hyperinsulinemia euglycemia therapy) as first-line therapy in poisoning with calcium-channel blockers (9). A number of potential explanations for its action have been suggested, from the inherent activity of insulin as a positive inotrope to the hypothesis that it acts by improving carbohydrate metabolism in cardiac myocytes (10,11). By antagonizing pancreatic L-type calcium channels, calcium-channel blockers restrict insulin secretion by pancreatic beta cells and may produce hyperglycemia (12).…”