[Vasoactive intestinal peptide attenuates apoptosis and iNOS protein expression induced by cerebral ischemia in the rat].

Objective: To explore the neuroprotective action of vasoactive intestinal peptide (VIP) on ischemia and reperfusion in the rat.
Methods: VIP was given via intracerebroventriclar injection after a 2 hour transient middle cerebral artery occlusion using filament model. The infarct volume was investigated with TTC stain. Apoptosis in the ischemic boundary zone were evaluated with TUNEL stain. Western blotting were used to analyze the iNOS protein expression as well.
Results: After VIP injection, the relative infarct volume of rats was significantly reduced by approximately 28% campared to that of the control groups at 1 day (P < 0.05). The number of TUNEL positive cells was significantly decreased in the ischemic boundary zone, and then the expression of iNOS was remarkablely decreased as well (P < 0.05).
Conclusion: VIP has a neuroprotective effect on cerebral ischemia and reperfusion. The mechanism seems to involve decreasing the apoptosis and down-regulating the iNOS expression.