Restricted feeding improves post-ischemic recovery of Langendorff perfused rat hearts.

MARÍA DEL MAR JAITOVICH; ALICIA VARELA; CINTIA SBARBATI; ROMINA HERMANN; MARÍA EMILIA TORRESÍN; ENRIQUE A. SAVINO; M.G MARINA PRENDES

CANADIAN JOURNAL OF PHYSIOLOGY AND PHARMACOLOGY (ONLINE)

NRC Research Press

Año: 2010 vol. 88 p. 1002 - 1009

1205-7541

The goal of the present study was to assess the effects of a restricted feeding schedule (RFS) on post-ischemic contractile recovery in relation to triacylglycerol (TAG), glycogen and ATP content. Glucose-6-phosphate-dehydrogenase (G6PDH) activity, reduced/oxidized glutathion ratio (GSH/GSSG) and thiobarbituric-acid-reactive-substances (TBARS) level were also determined. Isolated rat hearts entrained to daily RFS (2-hour food access starting at 12.00 noon) or fed ad libitum (FED) for three weeks were Langendorff-perfused (25-minute ischemia, 30-minute reperfusion) with Krebs-Ringer-bicarbonate (10 mM glucose). RFS improved the recovery of contractility and reduced CK release upon reperfusion. Further, at the end of reperfusion, RFS hearts exhibited increased G6PDH activity and repletion of tissue glycogen, TAG and ATP that was not observed in the FED hearts. GSH/GSSG at the end of reperfusion fell to the same value in both nutritional states and TBARS levels were higher in the RFS hearts. In conclusion, RFS improved post-ischemic functional recovery, which was accompanied by a reduction in CK release and a striking energy recovery. Notwithstanding, although enhanced G6PDH activity was displayed, RFS was unable to reduce lipid peroxidation, supporting a clear dissociation between protection against mechanical dysfunction and CK release on the one hand and oxidative damage on the other.