Perfusion of isolated, nondiabetic rat hearts with high concentrations of regular insulin (10 mU/ml) produced earlier onset of myocardial contracture during ischemia than control perfusions without insulin. High insulin concentrations also increased total myocardial calcium content (p < .001) and myocardial Ca-45 uptake postischemia (p < .05). Insulin perfusion before ischemia did not enhance calcium uptake. These results support the hypothesis that insulin may increase calcium movement across myocardial cell membranes, which may lead to increased ischemic contracture. Insulin-aggravated myocardial ischemia in cardiothoracic surgery and cardiac resuscitation deserves further investigation.
ASJC Scopus subject areas
- Critical Care and Intensive Care Medicine