Effect of prenatal ethano exposure on myelin proteins and discrimination learning in rat offspring

我们先前发现，子宫内乙醇暴露会影响子代大鼠髓鞘碱性蛋白(MBP)和2‘，3’，环核苷酸3‘-磷酸二酯酶(CNP)基因的发育表达。本研究观察了孕期酒精暴露对仔鼠的髓鞘蛋白、蛋白脂蛋白(PLP)和髓鞘相关糖蛋白(MAG)以及辨别学习能力的影响。用亚临床剂量的乙醇对妊娠大鼠进行腹腔注射。通过细胞总RNA的Northern印迹分析，检测不同发育时期PLP和MAG基因的编码水平。与对照组相比，孕期酒精暴露大鼠胎鼠大脑中PLP和MAG基因的表达明显延迟。提示MBP和CNP的表达模式不同于PLP和MAG。综合目前和以前的研究结果，孕期酒精暴露对大鼠所有髓鞘蛋白的mRNA水平都有影响，尽管这种影响在不同的蛋白质种类中是不同的。在操作型学习程序下，训练大鼠区分开灯和关灯状态。未发现胎儿期酒精暴露大鼠与对照组之间的辨别率，但胎儿期酒精暴露大鼠的总反应数高于对照组。两组间差异有统计学意义(P&lt；0.05)。

We previously found that developmental expression of mRNAs coding for myelin basic protein (MBP) and 2', 3', cyclic nucleotide 3'-phosphodiesterase (CNP) of rat offspring exposed to ethanol in uterus was affected. In this study, we examined the effects of prenatal ethanol exposure on myelin protein, proteolipid protein (PLP) and myelin associated glycoprotein (MAG), and discrimination learning ability in the rat offsprings. Subclinical dose of ethanol was administered intraperitoneally to pregnant rats. The levels of mRNA coding for PLP and MAG at various developing periods were examined by Northern blot analysis of total cellular RNAs. The expressions of PLP and MAG mRNA in rats prenatally exposed to ethanol were delayed as to the developmental pattern compared with those of control rats. It is suggested that the expression patterns of MBP and CNP were different with those of PLP and MAG. Taking together the present and previous findings, the prenatal ethanol exposure to rats affects all myelin proteins at their mRNA level, although the effects were different in different protein species. Rats were trained to discriminate between lamp-on and lamp-off states under an operant-type learning procedure. The discrimination ratio between rats prenatally exposed to ethanol and the control were not found, but the number of overall responses in rats exposed prenatally ethanol were higher than control rats. The differences between two groups were statistically significant (P<0.05).