HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 233/9/1142    most recent 0801-RM-33v1 Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Liang, G.-Y. Articles by Xu, G. PubMed PubMed Citation Articles by Liang, G.-Y. Articles by Xu, G.

---

ORIGINAL RESEARCH ARTICLE

Cardiac Glucose Uptake and Suppressed Expression/Translocation of Myocardium Glucose Transport-4 in Dogs Undergoing Ischemia-Reperfusion

Affiliated Hospital of Zunyi Medical College, Department of Thoracic and Cardiovascular Surgery, Zunyi, Guizhou 563003, China

To whom requests for reprints should be addressed at ¹ Affiliated Hospital of Zunyi Medical College, 149 Da-Lian Road, Zunyi, Guizhou 563003, China. E-mail: guiyou515{at}163.com

Impaired glucose metabolism is implicated in cardiac failure during ischemia-reperfusion. This study examined cardiac glucose uptake and expression of glucose transport-4 (GLUT-4) in dogs undergoing ischemia-reperfusion. Cardiac ischemia was induced by cardiopulmonary bypass for 30 min or 120 min in dogs. Plasma insulin and glucose concentrations were measured at pre-bypass (control), and aortic cross-clamp off (ischemia-reperfusion) at 15, 45, and 75 min. At the same time, the left ventricle biopsies were taken for GLUT-4 immunohistochemistry and glycogen content analysis. In dogs receiving 120-min ischemia, coronary arterial and venous glucose concentrations were increased, but the net glucose uptake in ischemia-reperfusion heart were significantly decreased from 25% (control) to zero at 15 and 45 min of reperfusion, and recovered to only 7% after 75 min reperfusion. Myocardium glycogen contents were decreased by 65%. Plasma insulin levels and Insulin Resistant Index were markedly increased in dogs undergoing 120-min ischemia and reperfusion. These changes were relatively mild and reversible in dogs receiving only 30-min ischemia followed by reperfusion. Expression of total GLUT-4 in myocardium was decreased 40% and translocation of GLUT-4 from cytoplasm to surface membrane was decreased 90% in dogs receiving 120-min ischemia followed by 15-min reperfusion. Suppressed translocation of GLUT-4 was also evident in dogs receiving 30-min ischemia, but to a lesser extent. Reduced myocardium glucose uptake, utilization, and glycogen content are clearly associated with ischemia-reperfusion heart injury. This appears to be due, at least in part, to suppressed expression and translocation of myocardium GLUT-4.

Key Words: cardiopulmonary bypass • ischemia-reperfusion • dog • myocardial glucose uptake • insulin resistance • glucose transport-4