6-Mercaptopurine이 백서 간에 미치는 영향에 관한 조직학적 및 조직화학적 연구
Histological and histochemical studies of the effects of 6-Mercaptopurine on the liver in rats
항암제인 6-mercarcaptopurine(6-MP)은 purine합성을 억제하며, 주로 백혈병의 치료에 이용된다.
6-MP의 부작용으로는 골수기능저하, 위장장애 및 간기능장애등이 흔히 알려져 있고 그중에서 간기능장애를 일으킨 임상보고가 다수 있으며, 황달, 간괴사, 담즙정체등이 나타난다고 했으나, 6-MP가 간에 미치는 영향에 관한 실험적연구는 드물다.
Glucose-6-phosphatase(G-6-Pase)는 간에 많이 존재하는 microsomal enzyme으로서 간세포에 변화가 오는 경우 조직학적변화에 앞서서 효소활성이 변화한다고 한다.
본 연구는 6-MP의 용량을 변화시켜 백서에 투여한후 간세포에 미치는 영향을 hematoxylin-eosin염색에 의한 조직학적방법 및 oil red 0 염색법, periodic acid-Schiff염색법, G-6-Pase활성 염색법등의 조직화학적방법으로 관찰하여 다음과 같은 결과를 얻었다.
1. Hematoxylin-rosin염색소견은 6-MP 50mg/kg투여군에서 공포가 나타나기 시작했으며, 용량이 증가함에 따라 지방변성 및 간괴사를 초래했다.
2. Oil red 0염색소견은 50mg/kg투여근에서 처음 지방소적이 관찰되었으며 용량의 증가에 따라 점차 지방이 증가되었다.
3. Periodic acid-Schiff염색소견은 6-MP 25 mg/kg투여군에서 glycogen양이 감소하였고, 용량이 증가함에 따라 glycogen감소가 심해졌다.
4. G-6-Pase활성변화는 6-MP 10mg/kg투여군부터 활성이 감소하기 시작하였으며, 6-MP 100mg/kg투여군에서는 G-6-Pase활성은 완전히 소실되었다.
이상의 결과로 보아, 효소조직화학적방법인 G-6-Pase활성 염색법이 다른 조직학적 및 조직화학적 방법보다도 조기에 6-MP의 간독성을 검출할 수 있을 것으로 사료된다.
6-Mercaptopurine (6-MP) inhibit DNA synthesis by interfering with the production of purine bases, and is used mainly in the treatment of leukemia. Toxic effect of 6-MP are bone marrow depression, gastrointestinal disturbance and liver dysfunrtion. Jaundice, cholestasis and hepatic necrosis occures during the course of 6-MP therapy in human, has been mentioned occasionally in the literature.
Hepatotoxicity of 6-MP in experimental animals has been rarely reported and is limited only histopathologic changes after administration of sublethal dose.
Glucose-6-phosphatase (G-6-Pase) is a specific enzyme occuring in considerable amounts in the liver and activity of G-6-Pase may change when the hepatocellular activity is altered.
Alteration of G-6-Pase activity may appear earlier than general histopathological changers.
The present study was undertaken to investigate the hepatotoxicity of 6-MP in the rat and to examine relationship between the morphologic change and the G-6-Pase activity according to changes of 6-MP dosage: Hematokyline-eosin (H-E) stain for general histologic alteration, oil red O stain for fat deposition, periodic acid-Schiff (PAS) stain for the glycogen distribution, and modified Wachstein-Meisel stain for G-6-Pase activity were used.
The results are summerized as follows :
1. Hematoxyline-eosin stain; Cell swelling and vacuolization of hepatic cell appeared in the 50mg/kg 6-MP administration group, by increasing dose of 6-MP, fatty change and hepatic necrosis also appeared.
2. Oil red 0 stain; Fat droplets were noted in 50mg/kg 6-MP administration group, and marked increase in fatty material were shown by increasing the dose of 6-MP.
3. Periodic acid-Schiff stain; A slight decrease in glycogen was noted in the 25mg/kg 6-MP administration group, and increased dose of 6-MP resulted in further decreased in glycogen.
4. G-6-Pase activity; Activity of G-6-Pase was slightly decreased in 10mg/kg 6-MP administraton group. As the dose of drug administration increased, activity of G-6-Pase progressively decreased. Activity of G-6-Pase disappeared in the 6-MP 100mg/kg administration group.
The above results showed that the study of G-6-Pase activity could detect earlier changes of hepatotoxicity induced by 6-MP comparing to the other histological and histochemical methods.