Effect of 2-6 Diaminopurine (2-6 DP): 6 Chlorpurine (CIP) and Thioguanine (ThG) on Rat Litter in Utero.

Abstract

1. 2-6-DP, CIP and ThG were given to groups of pregnant rats in 2 doses of 5 LD₅₀, not toxic to the mother animals. The compounds were given on the 4th and 5th, or on the 7th and 8th, or on the 11th and 12th days of gestation. 2. 2-6-DP showed a peak of action on the fetuses and litters when given before implantation, destroying 75% of all the fetuses, but only 57% of all the litters. 3. CIP showed a peak of action on the 7th and 8 th days, destroying all fetuses and litters. Treatment on days 4 and 5 of gestation destroyed 69% of the fetuses, but only 32% of all litters. At midterm, no litter was completely destroyed, and only 10% of all the fetuses were resorbed. However 50% of all survivors were stunted and malformed. 4. ThG was the most toxic compound to the fetuses. At the time of implantation it destroyed all fetuses. On days 4 and 5 of gestation, it led to resorption of 75% of the fetuses, but only to 10% complete litter destruction. At midterm it still destroyed 61% of all fetuses, and 43% of all litters, while stunting 37% of all survivors. 5. The lethal action of CIP and ThG on the rat litter at implantation time could not be prevented by progesterone administration.