OBJECTIVETo explore the mechanism of neurotoxicity induced by manganese, and observe the effects on the apoptosis of neurons in rat striatum.

METHODSSD rats were divided into four groups, six rats each group. Three dose groups were exposed to high, middle, and low level of MnCl(2). At the end of experiment, all rats of the exposed groups and control group were decapitated, their striatums were removed and the Mn content of striatum, the apoptotic morphology, ratio and ultrastructural organization were analyzed.

RESULTSThe Mn content of striatum and apoptosis index of the three dose groups exposed to high, middle, and low level of Mn were significantly higher than control group (P < 0.05). The Mn content of striatum of the three dose groups exposed to high, middle, low level of MnCl(2) and control group were 2.98 +/- 0.52, 2.75 +/- 0.37, 2.61 +/- 0.73, 0.60 +/- 0.20 respectively. The apoptosis index of striatum of the three dose groups exposed to high, middle, low level of MnCl(2) and control group were 24.83 +/- 5.98, 17.00 +/- 5.33, 15.33 +/- 2.58, 2.83 +/- 0.41 respectively, and following higher level dose, the apoptosis index increased. The nucleus of neurons in striatum become smaller, condensed, etc, and these character showed apoptosis of neurons.

CONCLUSIONMn can result in apoptotic morphology and increase level of apoptosis in striatum. The level of apoptos varies with Mn concentration.