Serum was separated for estimation of specific serum marker enzymes, namely, lactate dehydrogenase (LDH) [21, 22] and creatine kinase (CK) [23]. STZ-induced oxidative stress in diabetes is also a predictor of cardiac damage. Since LDH and CK are specific cardiac marker enzymes, increased serum LDH and CK levels were considered as marker of oxidative stress-induced cardiac damage.