Fffects of Testosterone Propionate on Neonatal and Prepuberal Development of Os Penis in Male Rats

Abstract

Osteogenesis in the penial bone was observed in male rat: immature stromal cells of mesenchymal origin appeared in the penis on the 21st day of fetal age and developed to form mature bony structure with the bonemarrow on or before day 7 after birth; the bone was 1.41±0.12 mm in length. Neonatal castration caused maldevelopment of the genial bone, while prepuberal treatment with testosterone propionate stimulated the bony growth in castrated immature rat. These results suggest that the stromal cells in penile part of newborn male rats have already been destinated to develop into os penis by fetal exposure to androgen and they do not require androgens for further differentiation but for the bony growth after birth.