Effect of hyperglycemia on ischemia/reperfusion-induced ventricular arrythmia in isolated diabetic rat hearts
- VernacularTitle:高糖灌注对糖尿病大鼠离体缺血再灌注心脏心律失常及肌酸激酶的影响
- Author:
Tao LIU
;
Libing CHEN
;
Meiying XU
- Publication Type:Journal Article
- Keywords:
Diabetes;
Myocardial reperfusion injury;
Arrhythmias
- From:
Chinese Journal of Anesthesiology
1996;0(09):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective There is still controversy over the effect of hyperglycemia on the tolerance of heart to ischemia/reperfusion(I/R)injury in patients with diabetes mellitus. The aim of this study was to evaluate the effect of hyperglycemia on I/R-induced ventricular arrythmia in isolated diabetic rat hearts. Methods Twenty-four healthy male SD rats weighing 210-250g were randomly divided into two groups: control group(C, n=10) and diabetes mellitus group(DM, n=14). Diabetes mellitus was induced by intraperitoneal injection of streptozotocin 60 mg?kg~(-1). Blood glucose was measured 72h later and every week thereafter. Diabetes mellitus was defined as persistent hyperglycemia(blood glucose≥16.7 mmol/L after meal). The diabeticrats received no insulin. The rats were anesthetized with pentobarbital 60mg?kg~(-1). The hearts were immediately removed and perfused with oxygenated(95% O_2, 5% CO_2)Krebs-Henseleit buffer(KHB)in a Langendorff apparatus at a constant perfusion pressure of 80 mm Hg. The 14 diabetic rats were further divided randomly into 2 subgroups: (1)DM+KHB (n=7) and (2) DM+GLU(n=7) in which glucose 3.6 g was added to KHB 1000ml. After 20 min equilibration all hearts were subjected to 30 min global ischemia followed by 40 min reperfusion. Epicardial electrocardiogram was monitored. The incidence of ventricular tachycardia(VT) and ventricular fibrillation(VF) and their duration were measured. The severity of arrhythmia was quantified by arrythmia score(AS). Coronary outflow was collected for determination of creatine kinase(CK) release. Results The incidence of ischemia-induced arrythmia was significantly lowered in diabetic hearts. The incidence of VT was 14.3% and VF 28.6% in DM+KHB subgroup as compared to 60%(VT) and 100%(VF) in the control group. The CK release was significantly lower in diabetes group(DM) than in control group(C); furthermore the CK release in DM=KHB subgroup was lower than that in DM=GLU subgroup. Conclusion Diabetic rat hearts are less susceptible to I/R induced arrythmia. Hyperglycemic perfusion reduces to some extent the increased tolerance to I/R injury in diabetic rat hearts as shown by increased CK release in DM+GLU subgroup but hyperglycemic perfusion has anti-arrhythmic action as shown by 0% incidence of VT and VF in DM+GLU subgroup.
