INS and diabetic cardiomyopathy: In a 1981 study, two groups of rats previously treated with streptozotocin were either treated or not treated with insulin therapy to investigate whether acute diabetic cardiomyopathy associated with insulin deficiency could be reversed [47]: the insulin-treated rats showed complete reversibility of the papillary muscle after 28 days, demonstrating that the diabetic cardiopathy was reversible and that this condition was not related to streptozotocin toxicity but rather to insulin deficiency [47].