Tajuddin N F, Druse M J
Department of Molecular and Cellular Biochemistry, Loyola University of Chicago, Stritch School of Medicine, Maywood, Illinois 60153, USA.
Alcohol Clin Exp Res. 1998 Aug;22(5):1152-60.
We examined the combined effects of chronic ethanol consumption and aging on mRNA and peptide for proenkephalin (PE), the precursor of met- and leu-enkephalin. This study also evaluated the effects of aging and alcohol on the level of the mRNA encoding the common precursor of neurotensin (NT) and neuromedin N (NN). PE mRNA and NT/NN mRNA were quantitated in multiple brain areas of 5- and 24-month-old male Fischer 344 rats. Aging, but not chronic ethanol consumption, altered PE mRNA and peptide levels. Aging was accompanied by a loss of PE peptide and PE mRNA in the rostral striatum. In aged rats, PE mRNA was also reduced in the shell region of the nucleus accumbens. The decline in PE mRNA in the rostral striatum and shell region of the nucleus accumbens was caused by a reduction in the number of cells that contain PE mRNA. The percentage of PE mRNA-containing neurons that express a high amount of PE mRNA was also lower in the rostral striatum of 24-month-old rats. The effects of aging may impair motor function and alter the rewarding properties of ethanol consumption. Neither aging nor alcohol changed the PE mRNA levels in the core region of the nucleus accumbens, the frontal cortex, and the piriform cortex. In contrast to PE mRNA, neither aging nor chronic ethanol consumption affected NT/NN mRNA in the regions analyzed. Normal NT/NN mRNA levels were found in the lateral septum and two hippocampal brain areas: the dorsal subiculum and CA1 regions.
我们研究了长期乙醇摄入与衰老对脑啡肽原（PE）mRNA和肽的联合影响，脑啡肽原是甲硫氨酸脑啡肽和亮氨酸脑啡肽的前体。本研究还评估了衰老和酒精对编码神经降压素（NT）和神经介素N（NN）共同前体的mRNA水平的影响。对5月龄和24月龄雄性Fischer 344大鼠的多个脑区中的PE mRNA和NT/NN mRNA进行了定量分析。衰老而非长期乙醇摄入改变了PE mRNA和肽的水平。衰老伴随着喙状纹状体中PE肽和PE mRNA的减少。在老年大鼠中，伏隔核壳区的PE mRNA也减少。喙状纹状体和伏隔核壳区PE mRNA的下降是由于含有PE mRNA的细胞数量减少所致。在24月龄大鼠的喙状纹状体中，表达大量PE mRNA的含PE mRNA神经元的百分比也较低。衰老的影响可能损害运动功能并改变乙醇摄入的奖赏特性。衰老和酒精均未改变伏隔核核心区、额叶皮质和梨状皮质中的PE mRNA水平。与PE mRNA相反，衰老和长期乙醇摄入均未影响所分析区域中的NT/NN mRNA。在外侧隔区以及两个海马脑区：背侧下托和CA1区中发现了正常的NT/NN mRNA水平。
