Influence of castration on development of the thymus in neonatal male rats.
The influence of castration on the development of the thymus in neonatal rats was studied to elucidate when after birth the thymus comes under inhibitory regulation by the testis in rats. The relative and absolute weights of the thymus were measured five days after castration these cases. No excessive changes in the weights of the thymus with castration were observed by 31 days after birth. Significant changes in the thymus appeared in the relative weight at 36-day-castration. The absolute weight of the thymus was also significantly increased after 41-day-castration. These findings suggest that in rats the inhibitory regulation of the thymus by testis development does not appear before at least 31 days of age.
Shioya
N
N
Department of Laboratory Animal Science, School of Veterinary Medicine, Azabu University, Kanagawa, Japan.
Inomata
T
T
Ninomiya
H
H
Nakamura
T
T
D000375:Aging; D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development*; D002369:Castration; D006984:Hypertrophy; D008297:Male; D009929:Organ Size; D051381:Rats; D017207:Rats, Sprague-Dawley; D013737:Testis / Q000254:growth & development / Q000502:physiology; D013950:Thymus Gland / Q000254:growth & development* / Q000473:pathology