Preconditioning offers cardioprotection in hyperlipidemic @entity35 hearts: possible role of XXXX (D2) signaling.

@entity407 @entity1088 @entity63 @entity935 @entity908 @entity1188 @entity880 @entity35
BACKGROUND: Ischemic preconditioning (IPC) induced cardioprotection has been reported to be blunted in hyperlipidemic subjects. @entity935 , via its D2 receptor signaling, appears to mimic the signaling cascade involved in myocardial preconditioning and is also involved in the inhibition of @entity407 induced mediators. The present study was designed to investigate the possible involvement of D2 receptors in IPC and to see whether @entity935 preconditioning can offer cardioprotection in hyperlipidemic @entity35 hearts. METHODS: @entity35 albino @entity35 were divided into 8 groups and fed on normal or high fat diet for 4  weeks. @entity407 was confirmed after 4  weeks by serum lipid estimations. Isolated perfused hearts were subjected to @entity63 preconditioning or @entity935 induced pharmacological preconditioning followed by 30-min @entity63 insult and 60-min reperfusion. @entity1088 was administered as D2 antagonist. Coronary perfusate (basal and post- @entity63 ) was collected for the estimations of LDH ( @entity880 dehydrogenase) and CKMB ( @entity908 kinase MB). Hearts were then removed and frozen for @entity1188 size measurement. RESULTS: A significant increase body weight, serum lipids except HDL was noted in high fat diet fed @entity35 , as compared to normal @entity35 . The level of LDH, CKMB in coronary effluent and @entity1188 size were found to be decreased in preconditioned normal hearts, as compared to hearts treated with @entity63 reperfusion. This effect was found to be blunted in hyperlipidemic animals. @entity935 (10   M) alone and in combination with @entity63 preconditioning significantly reduced the levels of LDH, CKMB and @entity1188 size in hyperlipidemic hearts, as compared to preconditioned and non-preconditioned hyperlipidemic hearts. This effect was abolished significantly by @entity1088 (D2 antagonist). CONCLUSION: The present study reveals possible involvement of D2 receptors in @entity63 preconditioning and suggests that @entity935 preconditioning may offer significant cardioprotection in hyperlipidemic @entity35 hearts.
