PAS-Na On Manganese Poisoning On Learning And Memory Functions And Hippocampal Expression Of GFAP

Objective: To explore the effects of sodium para-aminosalicylic acid (PAS-Na) on learning memory and expression of glial fibrillary acidic protein (GFAP) positive cells in hippocampus of subacute manganese(Mn)-exposed rats.Methods:144 male Sprague-Dawley rats were randomly divided into the control, Mn-exposed, PAS-Na prevention group. The Mn-exposed rats received daily intraperitoneally injections (i.p.) of manganese chloride (MnCl2·4H2O 15mg/kg), one time a day , 5 days/week for 12 weeks, The control group were injected with the same Capacity saline。PAS-Na prevention group in the same time exposed to manganese 1,3,5 days a week subcutaneous injection (sc) PAS-Na 200mg/kg, Manganese in the dye after the end of 12 weeks of Mn group was randomly divided into control group exposed to manganese (Mn in group), PAS-Na treatment group,The treatment group after 12 weeks of Mn given subcutaneous injection of PAS-Na 200mg/kg, Exposed to manganese group and control group were given subcutaneous injection of the same volume of saline, 1 day, 3 days per week for 6 weeks.The ability of learning memory was tested by Morris Water Maze (MWM) and the GFAP-positive cells in the hippocampal CA1 area and dentate gyrus was detected by immunohis to chemical technique.Results:The weight gain of Mn-exposed group was evidently reduced in 12 weeks and still lasted 18 weeks after suspending Mn exposure (P<0.05). In the 18 week,The escape latency of Mn-exposed group were longer than those of the control group but(P﹥0.05), In the 1,2 days ,The total swimming distance of PAS-Na treatment group were shorter than those of the Mn-exposed group(P<0.05).In the 6 week,12 week and 18 week GFAP positive cells in the manganese-exposed group increased compared with that of control group(P <0.05～0.01),In the 12 week ,GFAP positive cells in the manganese-exposed group decreased compared with that of manganese-exposed group,But still more than the control group。Conclusions : PAS-Na may have the intervention effect on growth retardation,learning and memory impairment, glial abnormal proliferation in hippocampus of rats induced by manganese.