Regulation of prostatic growth. Growth-limiting mechanisms in the rat ventral prostate

The possibility that a prostatic chalone is a factor regulating growth of the gland was investigated in rats submitted to hemiprostatectomy to reduce the level of a hypothetical circulating chalone. No evidence of regeneration was found 4 weeks postoperatively. Orchiectomized rats with intrasplenic, intramuscular or intraprostatic implants of ventral prostatic tissue from other orchiectomized rats, were given androgen. The cell divisions in the prostatic tissue did not end until the total cell number was 150-170% of that in control rats. These results indicate that other factors than a prostatic chalone have a dominant role in the mechanism limiting prostatic growth. As introduction of an artificial stroma led to increased prostatic growth, it appears likely that the fibromuscular stroma is one of the factors controlling growth of the prostatic epithelial cells.