Prostatic growth effects of rat urogenital sinus and human prostatic tissue in the rat

It is known that fetal urogenital sinus (UGS) implanted into one ventral lobe of an adult mouse prostate produces a significantly increased DNA content in that lobe. In our study, we attempted to determine whether that growth was of host or of graft tissue. UGS from fetal rats and ventral prostate from adult rats were implanted in various sites in syngeneic Fischer rats, alone or as a recombinant tissue complex. Human benign prostatic hyperplasia (BPH) tissue was implanted into the ventral prostate of adult, male, hooded nude rats to determine whether it stimulated prostatic growth. All UGS-implanted in situ ventral lobes enlarged. Mean DNA content of UGS and ventral prostate implanted together in the flank was not different from the mean DNA content of UGS and ventral prostate implanted separately in the flank (P = 0.69). Mean DNA content of in situ control ventral lobe and of UGS grown singly in the flank was less than that of a UGS-implanted in situ ventral lobe (P less than 0.01). Thus overgrowth in the UGS-implanted in situ ventral prostate was location-dependent, but which tissue(s) enlarged remains unclear. Implanted human BPH tissue did not stimulate rat prostatic growth.