Abstract: The effects of puerarin(pue), an effective component of a Chinese herb, against astrocyte swelling in cultures and brain edema intact rats were studied. Astrocyte swelling in culture was induced with trans-1-aminocyclopentane-1, 3-dicarboxylic acid(tACPD), an agonist of metabotropic glutamate receptors. tACPD(1mmol/L)alone or with pue(1mmol/L)were added in culture at 37 ℃ for 1 h, then the intracellular water space(IWS)was measured by ³H-3-O-methyl-D-glucose. For in vivo study, brain edema was induced with tACPD(500nmol)in 2 μL injected stereotactically into right caudatum of the rat. Pue(50mg/kg)was administered intraperitoneally on the 1st and 2nd day, and intravenously on the 3rd day, then followed by intracaudatal injection of tACPD. Sixh after tACPD injection brain water content and Na⁺, K⁺, Ca²⁺ contents were determined. Histological study was performed with electron microscope(EM). It was showed that pue blocked the increase of IWS induced by tACPD in astrocyte culture and reduced the increases of brain water and Na⁺ contents induced by tACPD in vivo. Furthermore, astrocyte swelling and the constriction of capillary lumen induced by the pressure of swelling endfeet of astrocytes, which were observed in tACPD treated rats under EM, were attenuated by pue treatment. The results indicats that pretreatment with pue can prevent astrocyte swelling and brain edema induced by tACPD, which may be beneficial to brain microcirculation during hypoxia and ischemia.

Key words: astrocyte swelling, brain edema, puerarin