| Abstract: | ![]()
On the day of birth, pups of Swiss strain mice were assigned to two groups: A (one male pup reared with mother alone, and B (3 male pups and 3 female pups with their mother). Animals were sacrificed at 1, 20, 40, 60 and 90 days. Pups of both groups were weaned on 20th day. At weaning, after removal of the mother, males of Group A stayed one per cage until sacrifice, while in Group B they stayed in cohabitation with females (3 males and 3 females per cage). In Group B, litters which appeared in the cages indicated the first fertile copulations occurred about 38–40 days. Males of Group A are sexual naîve males. Testosterone was measured by RIA. Compared to males of Group B, the testicular growth of Group A males was slower from 1 to 20 days, then more rapid from 20 to 60 days, and was prematurely stopped at this stage while it continued until Day 90 in males of Group B. From 1 to 40 days, testicular and plasma testosterone levels followed a similar pattern in the two groups. From 40 to 90 days testosterone level decreased significantly in the plasma and in the testis of animals of Group B, while it remained stable in Group A males. The results showed that, in mice, social deprivation as soon as birth and therefore lack of sexual experience, modify testicular growth as well as testosterone synthesis and secretion. |
