摘要

Pregnant rats were treated daily with 1 g/L of L-glutamate in their drinking water during pregnancy and/or lactation. The effect on adenosine A, receptor (A,R) and A(2A) receptor (A R) in brains from both mothers and 15-day-old neonates was assayed using radioligand binding and real time PCR assays. Mothers receiving L-glutamate during gestation, lactation, and throughout gestation and lactation showed a significant decrease in total A(1)R number (water+water, 302+/-49 fmol/mg; L-glutamate+water, 109+/-11 fmol/mg, P<0.01; water+L-glutamate, 52 13 fmol/mg, P<0.01; L-glutamate+L-glutamate, 128+/-33 fmol/mg, P<0.05). No variations were detected in the Kd parameter. Concerning adenosine A R, radioligand binding assays revealed that Bmax parameter remains unaltered in maternal brain in response to glutamate exposure. However, Kd parameter was significantly decreased in all L-glutamate-treated groups (water+water, 5.3+/-1.3 nM; L-glutamate water, 0.5+/-0.1 nM; water+L-glutamate, 0.9+/-0.1 nM; L-glutamate L-glutamate, 0.7+/-0.1 nM, P<0.01 in all cases). In both male and female neonates, A(1)R was also decreased after long-term glutamate exposure during gestation, lactation, and gestation plus lactation (male neonates: water+water, 564 68 fmol/mg; L-glutamate+ water, 61+/-8 fmol/mg; water+L-glutamate, 95 20 fmol/mg; L-glutamate+L-glutamate, 111+/-15 fmol/mg; P<0.01 in all cases; female neonates: water+water, 216+/-35 fmol/mg; L-glutamate+ water, 59+/-9 fmol/mg; water+L-glutamate, 139+/-16 fmol/mg; L-glutamate+L-glutamate, 97+/-14 fmol/mg; P<0.01 in all cases). No variations were found in mRNA level coding adenosine A(1)R in maternal or neonatal brain. Concerning adenosine A(2A)R, radioligand binding assays revealed that Bmax parameter was significantly increased in male and female neonates exposed to L-glutamate during lactation (male neonates: water+water, 214+/-23 fmol/mg; water+L-glutamate, 581+/-49 fmol/mg; P<0.01; female neonates: water+water, 51+/-10 fmol/mg; water+L-glutamate, 282+/-52 fmol/mg; P<0.05). No variations were found in mRNA level coding adenosine A(2A)R in maternal or neonatal brain. In summary, long-term L-glutamate treatment during gestation and lactation promotes a significant down-regulation of A(1)R in whole brain from both mother and neonates and a significant up-regulation of A(2A)R in neonates exposed to L-glutamate during lactation.

  • 出版日期2011-12-29