肝ＵＤＰ‐ｇｌｕｃｕｒｏｎｙｌ　ｔｒａｎｓｆｅｒａｓｅ活性におよぼすグルカゴンの効果 Effect of glucagon on UDP-glucuronyl transferase activity

肝uridine diphosphate glucuronyl transferase (UDP-GT)活性が肝予備能の指標として有用なことに着目し,α-naphthyl isothiocyanate (ANIT)を用いた動物実験で,UDP-GT活性の変動とグルカゴン負荷試験時のcyclic AMPの変動が相似た傾向を示すことを認めた.UDP-GT活性はグルカゴンおよびdibutyryl cyclic AMP投与で,ANITによる肝細胞障害の程度に応じて上昇し,又,この酵素活性の上昇は蛋白合成阻害剤であるActinomycin Dによって阻害された.即ち,UDP-GT活性の酵素合成にcyclic AMPが関与することが示唆され,肝細胞障害時のUDP-GT活性とグルカゴン負荷後のcyclic AMPの変動の両者にcyclic AMPが介在することで,両者が相似た傾向を示すことが理解された.

We obserbed that uridine diphosphate glucuronyl transferase (UDP-GT) activity was a significant functional marker of hepatic reserve mass and that was a similar response between UDPGT activity and cyclic AMP by glucagon injection, glucagon tolerance test, in rats treated with alpha-naphthyl isothiocyanate (ANIT). Augmentation of UDP-GT activity was obtained by glucagon and dibutyryl cyclic AMP proportional to amount of liver cell injury and was inhibited by Actinomycin D, a known inhibitor of protein synthesis. There was indicated that cyclic AMP mediated glucuronyl transferase synthesis.