Abstract
Effects of intraperitoneal administrations of catecholamines, cyclic nucleotides and acetylcholine on 5- phosphoribosyl-1-pyrophosphate (PRPP)level in mouse liver have been investigated. ι-Epinephrine caused a marked increase in the level of PRPP, which was induced 5 to 10 min after the administration. ι-Phenylephrine and ι-norepinephrine showed moderate effects, while ι-isoproterenol gave no change of the PRPP level. The epinephrine-induced PRPP increase was completely blocked by the pretreatment of mice with α-adrenergic blocker, phenoxybenzamine, but not with β-blocker. Acetylcholine and carbachol also elevated the PRPP level in mouse liver, and this was inhibited by atropine pretreatment. In addition, both dibutyryl cyclic AMP and dibutyryl cyclic GMP significantly increased the liver PRPP level. There was a lag time of 5 to 10 min before induction of PRPP by dibutyryl cyclic AMP. Further experiments have to be taken in order to evaluate the role of cyclic nucleotides in the effect of catecholamin and acetylcholine on liver PRPP levels. In this report, we also discussed the role of PRPP in relation to a hyperuricemia induced by epinephrine.
