[Effect of the presence of females on the concentration of androgens in the male guinea pig at puberty].

At weaning (21 days), male guinea-pigs were assigned to three groups: A: two or three males with females in separate cages but in the same room; B: two males with one pubertal female in each cage; C: males without female in the environment. Animals were sacrificed on 50th day. Testosterone and androstenedione concentrations in the blood plasma and the testis were estimated by gas chromatography. The body and testicular weights of group C were lower than those of other groups. Testosterone and androstenedione levels in the plasma were lower in group C; testicular concentration of testosterone was similar in group A and C whereas level was weak in group B. Testicular concentration of androstenedione was increased with animals isolated of female. The results showed that, in guinea-pig at puberty, the presence or the lack of female, modify testicular weight and androgen concentration.