Effect of sodium para-aminosalicylic on concentrations of amino acid neurotransmitters in basal ganglia of manganese-exposed rats / 中华预防医学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To probe the effect of sodium para-aminosalicylate (PAS-Na) on concentration of amino acid neurotransmitters including glutamate (Glu), glutamine (Gln), glycine (Gly) and gamma-aminobutyric acid (GABA) in basal ganglia of subacute manganese (Mn)-exposed rats.</p><p><b>METHODS</b>Forty Sprague-Dawley male rats were randomly divided into the control, Mn-exposed, low dose PAS-Na (L-PAS) and high dose PAS-Na (H-PAS) groups. Rats in experiment groups received daily intraperitoneally injections of manganese chloride (MnCl₂ · 4H₂O, 15 mg/kg), while rats in control group received daily intraperitoneally injections of normal saline (NS), all at 5 days/week for 4 weeks. Then the rats in PAS groups followed by a daily subcutaneously dose of PAS-Na (100 and 200 mg/kg as the L-PAS and H-PAS groups, respectively) for another 3 and 6 weeks; while the rats in Mn-exposed and control group received NS. The concentrations of Glu, Gln, Gly and GABA in basal ganglia of rat was detected by the high performance liquid chromatography fluorescence detection technique.</p><p><b>RESULTS</b>After treating with PAS-Na for 3 weeks, the concentration of Gly in the Mn-exposed rats decreased to (0.165 ± 0.022) µmol/L (control = (0.271 ± 0.074) µmol/L, Mn vs control, t = 4.65, P < 0.05). After the further 6-week therapy with PAS-Na, the concentrations of Glu, Gln, Gly in the Mn-exposed rats were lower than those of the control rats ((0.942 ± 0.121), (0.377 ± 0.070), (0.142 ± 0.048), (1.590 ± 0.302), (0.563 ± 0.040), (0.247 ± 0.084) µmol/L; t = 7.72, 5.85, 4.30, P < 0.05); and also lower than in L-PAS and H-PAS groups, whose concentrations were separately (1.268 ± 0.124), (1.465 ± 0.196), (0.497 ± 0.050), (0.514 ± 0.103), (0.219 ± 0.034) µmol/L (L-PAS Glu and Gln vs Mn, t = 3.87, 3.77, P < 0.05; H-PAS Glu, Gln and Gly vs Mn, t = 6.78, 4.70, 3.42, P < 0.05).</p><p><b>CONCLUSION</b>The toxic effect of manganese on Glu, Gln and Gly in basal ganglia of Mn-exposed rats is obvious, especially appears earlier on Gly. The toxic effect still continues to develop when relieved from the exposure. PAS-Na may play an antagonism role in toxic effect of manganese on concentration of Glu, Gln and Gly in basal ganglia of Mn-exposed rats.</p>