GONADOTROPIN-REGULATED PRODUCTION OF IMMUNOACTIVE INHIBIN AND ANDROGEN BY CULTURED TESTICULAR CELLS FROM CHICKEN EMBRYOS

To study the potential intragonadal role of inhibin and inhibin-relate d proteins in the developing gonad, a method was developed to culture testicular cells of chicken embryos. A single-step collagenase/DNase d igestion was used to disperse the cells. Except for the primordial ger m cells and the erythrocytes, the cells attached well to plastic cultu re dishes. Moreover, they could easily be grown in the absence of seru m or other additives. Inhibin secretion was measured using a heterolog ous radioimmunoassay validated for use in this species. The fetal test icular cells secreted high amounts of immunoactive inhibin and remaine d responsive to gonadotrophins. Two different cell populations could b e recognized in monolayers of testicular cells: the first population h ad a fibroblast-like stromal appearance, resembling interstitial cells ; the second had an epitheloid appearance and contained large numbers of refractile vacuoles, resembling Sertoli cells. Both cell population s were enriched using a Percoll density gradient. The epitheloid cells displayed a higher capacity to secrete immunoactive inhibin, while th e stromal cells were responsible for the bulk of androgen secretion. F SH, but also LH, stimulated inhibin secretion in the epitheloid cells. Although ovine LH was the most potent stimulus for androgen secretion by the stromal cells, ovine FSH was also capable of increasing androg en output in stromal cells and to a lesser extent in epitheloid cells. As the two enriched cell populations were still contaminated by other cell types, this may indicate, as in other species, that FSH-induced paracrine factors are involved in the regulation of androgen secretion in the developing gonad. In conclusion, this fetal testicular cell cu lture system will provide a useful tool for further investigation of t he potential paracrine role of inhibin and its congeners during the de velopment of the gonads. (C) 1995 Academic Press, Inc.