Transplantations of isologous prostatic tissue in cleared mammary fat pads of BALB/c mice and F344 rats

The cleared inguinal (mammary) fat-pad of male and female BALB/c mice and F344 rats was found to be a suitable site for maintaining prostate transplants. Uncastrated syngeneic hosts were stimulated by testosterone propionate pellets implanted under their dorsal skin. Transplants survived in testosterone-stimulated male and female hosts for as long as 21 months, at which time the experiment was terminated. However, transplants did not survive in unstimulated female hosts. Histological examination of transplants in stimulated animals showed that the epithelial height was maintained and there was increased secretory activity. Attempts to maintain prostate transplants in spleen, kidney capsule, and in scapulat fat-pad for long periods were unsuccessful. Transplants at these sites survived for less than 1 year, the epithelium was low and irregular, and palpation of the transplants was difficult. The prolonged viability of prostate transplants in cleared inguinal mammary fat-pads should facilitate the study of the effects of carcinogens and/or hormones on the prostate.