OBJECTIVETo observe the temporal and spatial changes in the distribution of Ca2+ in the rat brain following focal cerebral ischemia injury and explore the protective effect of puerarin against calcium overload.

METHODSFocal cerebral ischemia was induced by middle cerebral artery occlusion in rats. After cerebral ischemia, puerarin was administered in the rats at different time points. The volume of ischemic cerebral tissue was assessed by TTC staining, and the fluorescence intensity of Ca2+ in the cortex and corpora striata was determined under laser scanning confocal microscope.

RESULTSThe fluorescence intensity of Ca2+ in the infracted cortex and corpora striata begun to increase 2 h after the ischemia and was further enhanced with the prolongation of the ischemic time. No significance was found in the fluorescence intensity of Ca2+ between the cortex and corpora striata. The fluorescence intensity of Ca2+ in the infarcted corpora striata was obviously higher than that in the cortex after ischemia. Compared with that in the ischemic model group, the fluorescence intensity of Ca2+ in the infarcted cortex and corpora striata decreased significantly at 2 and 12 h following puerarin intervention (P<0.05).

CONCLUSIONPuerarin treatment can relieve calcium overload, reduce cerebral ischemic volume and play a neuroprotective role against focal cerebral ischemia. Twelve hours following cerebral ischemic injury may be the time window for administering puerarin intervention.