Comparative studies on postnatal development of liver beta-glucuronidase activity between Gunn rats and Wistar rats

1. The changes of beta-glucuronidase activity in Wistar and Gunn strain rats from infants to adults, were determined. Consequently, the enzyme activity in liver was found to increase remarkably during the time of growth and to keep a certain level of activity at maturity. The beta-glucuronidase activity in Gunn strain rats was detected to be low in comparison with that of Wistar strain rats. 2. The beta-glucuronidase activity in liver of rats in over 50 days after birth is quite stable. It is concluded, therefore that the rats of 50-80 days old are most stable to examine the influence of drugs on beta-glucuronidase activity. 3. In the experiments using the above rats, the beta-glucuronidase activity in liver showed an increase by the administration of borneol, chloretone and barbital-Na. However, Gunn strain rats indicated rather low enzyme activity as compared to Wistar strain rats. 4. The beta-glucuronidase activity in kidney and intestine did not show an extensive alteration and was hardly affected by the drugs used.