레세르핀이 副賢과 腦幹에서 티로신 수산화효소와 페닐에타놀아민 엔-메틸전이효소의 組織特異發顯에 미치는 影響에 관한 研究

The Effect of Reserpine on Tissue Specific Egression of Tyrosine Hydroxylase(TH) and Phenylethanolamine-N-Methyltransferase(PNMT) in the Adrenal Medulla and Brain Stem

Objects : Reserpine which is most representative catecholamine-depleting drug was injected intraperitoneally to rats to explore tissue specific gene expression of TH and PNMT, which are each rate-limiting enzyme in cathecholamine biosynthesis and mark enzyme of epinephrine neuronal system, in brain stem and adrenal gland. Method : The enzyme activities and gene expressions of TH and PNMT in brain stem and adrenal gland were compared in respect to duation of drug administration. Results : 1) TH activities were increased in the brain stem each, by 28% (1.528± 0.081 nmole/mg protein/ hr) on 6 hours after administration of reserpine(5mg/kg) and by 40% (2.111± 0.152 nmole/mg protein/hr) on the last hour after four daily repeated intraperitoneal injections of reserpine(5mg/kg), when compared with the control group. Also TH activities in the adrenal gland were increased each, by 76%(19.613± 1.250nmol/mg protein/hr), and by 93 % (26.798± 0.906nmol/mg protein/hr), and by 93% (26.978± 0.906nmol/mg protein/hr) after the above mentioned treatment duration. 2) PNMT activities in brain stem and adrenal gland on 6 hours after reserpine administration (5mg/kg) were increased by ca. 20% (each 13.69士 1.84pmol/mg protain/hr, 1.22士 0.18nmole/mg protein/hr) in comparison with the control group. But the increase of PNMT activities after four daily repeated injections of reserpine(5mg/kg) were much greater(ca. 40~50%). 3) When comparing the amount of produced mRNA each other, increased TH mRNA gene expression was in positivie correlation with the increase of TH enzyme activity in adrenal gland and brain stem. Also, increased PNMT mRNA gene expression was in positive correlation with the increase of PNMT enzyme activity in adrenal gland, but in the brain stem PNMT mRNA gene expression was rather decreased oppositely to the increase of PNMT enzyme activiey. Conclusion : Above findings suggest that reserpine increases enzyme activity of TH through increased production of TH mRNA and that there is no difference in TH gene expression between central (brain stem) and peripheral (adrenal gland) nervous tissues, But PNMT gene expression was different between brain stem and adrenal gland. Brief discussion on this difference and other findings was done