苯丙酮尿症大鼠脑内单胺类递质的研究

A Study of the Brain Monoamine Transmitter in Phenylketonurea Rats

用3d 龄 Sprague-Dawley 大鼠,以 dl-对氯苯丙氨酸(PCPA)加 l-苯丙氨酸(Phe)腹腔注射7d,诱导大鼠苯丙酮尿症(PKU)。测定血清及脑组织中苯丙氨酸含量以及脑内去甲肾上腺素(NE)、多巴胺(DA)和5-羟色胺(5-HT)含量。实验发现,PKU 鼠血清中 Phe 浓度是正常对照组的16.5倍。脑内 NE、DA 及5-HT 含量除脑干中 DA 未见明显差异,其余均普遍降低。与 PCPA 组比较,PKU 鼠小脑中 NE、大脑皮层和海马中的 NE、DA 及5-HT 含量均有显著降低,其中海马中5-HT 含量降低40.9%(P<0.01)。可见,体内高浓度 Phe 对中枢单胺类递质影响与脑区相关。提示,大脑皮层和海马中单胺类递质的降低可能与 PKU 智力障碍密切相关。

Phenylketonuria(PKU)was induced in three-day old sprague-Dawley rats by daily intraperi- toneal injection with Phe(1.0/kg body wt.)plus PCPA(0.2g/kg body wt.)for 7 days.PCPA group rats were injected with 0.6% PCPA solution and normal control rats with normalsaline of the same dose.Fluorospectrophotometry was applied for guantitive determination of monoamine transmitter of the cerebellum,cerebral,cortex,brain stem and hippocampus in rats.The results showed that:serum Phe concentration of the PKU rats was 16.5 times that of the normal control 12 hours after the last in- jection.The contents of NE,DA and 5-HT in PKU rats showed different degree of decrease in various parts of the brain.Compared with the PCPA group,the contents of NE,DA and 5-HT decreased signif- icantly in the cerebral cortex and hippocampus of PKU rats,with the modt obrious decrease was 5-HT in the hippocampus,being 40.9%(P<0.01).The results indicate that mental retardation of PKU is in close relationship with the decrease of monoamine transmitter in the hippocampus and cerebral cortex.