Isolation of viable rat ventral prostate epithelial and nonepithelial cells.

Abstract

A procedure is described for the dispersion, partial purification, and identification of epithelial and nonepithelial cells from the rat ventral prostate, the latter based in part upon the ability of cells to bind androgen. Since initial efforts to mechanically disrupt prostatic tissue at 2 C lysed many cells, minced rat prostates were exposed to collagenase at 37 C and further dispersed by repetitive pipetting and passage through a tissue sieve. Washed cells in culture medium were centrifuged through an isokinetic Ficoll gradient from which three visible fraction (1, 2, and 4) and a less definite fraction 3 were harvested. Characterically, fraction 1 contained cellular debris; fraction 2 contained round nucleated cells, fewer elliptically shaped cells, red blood cells, and rare free cell nuclei; fraction 3 contained somewhat larger elliptical and round cells; and fraction 4 contained larger round and elliptically shaped cells. These were epithelial cells, as judged by electron microscopy. Isolated prostate cells from rats castrated for 24 h were incubated with [3H]testosterone; 80-90% of the retained radioactivity, the majority of which was dihydrotestosterone, was associated with washed cells from fraction 4. Similar results were obtained after in vivo administration of labeled androgen and subsequent analysis of radioactivity in cells from these fractions. Histochemically and enzymatically demonstrable formalin-insensitive acid phosphatase was increased in bands 3 and 4, which were enriched in epithelial cells. Many cells in fractions 2-4 were viable before and after exposure to Ficoll, as estimated by their ability to exclude trypan blue, incorporate radioactive uridine into RNA, generate cell monolayers during 1-4 weeks of culture, and actively metabolize androgens. Compared to fraction 4, cells from fraction 2, considered to be enriched in nonepithelial cells, actively metabolized but bound much less [3H]testosterone and its metabolites. A number of epithelial cells in fraction 4 isolated from prostates dissociated at 2 C were associated with typical-C-type RNA viruses.