THE EFFECTS OF FETAL SERUM AND GONADOTROPINS ON TESTOSTERONE PRODUCTION BY CULTURED CHICK TESTICULAR CELLS

This report describes the influences of fetal serum and gonadotropins on the development and function of chick testicular cells in a culture system that allows long term control of culture conditions. Testis of new born male chicks were dissociated and cultured in different condi tions and the production of testosterone measured by RIA. 1. To invest igate the effect of serum the cells were wither cultured in a defined medium composed by Dulbecco's modified medium (DMM) plus 0.1% albumin or media containing DMM plus 10% fetal bovine serum (FBS). The presenc e of serum increased protein content of the cultures, but no differenc es were found in basal testosterone production. When hCG (2IU/ml) was added to both culture media, the increment in testosterone production hence produced, was greater when cells were cultured in defined medium . 2. Cells were precultured for 24 hr in either defined serum media wi th or without hCG. The media were then replaced with DMM plus BSA and 1-methyl 3-isobutyl xanthine (IBMX) in the presence or absence of hCG and cells further incubated for 2 hr. Addition of hCG increased testos terone production by cells cultured in defined medium and enhanced its subsequent response to hCG stimulation. Cells cultured in serum mediu m maintained their ability to respond to hCG, but the addition of this hormone to the medium, abolished the response to further hCG-stimulat ion. 3. hCG caused a dose-related increased in testosterone production by cells cultured in defined and serum containing media, but concentr ations of hCG above 2 IU/ml depressed testosterone production in the l atter group. 4. Cells cultured in defined medium were incubated for 6 hr either with or without FSH of different purity grade. Both preparat ions stimulated the production of testosterone, the pure one being les s effective than the LH-contaminated one. 5. Cells cultured in defined medium were incubated for 6 hr either with or without FSH and further stimulated with hCG (2 IU/ml). A significant increment in the respons e to hCG was observed when cells had been exposed to FSH. Present resu lts show that FBS influences the function and development of chick tes tis cells in culture. Since both FSH and hCG modified testosterone sec retion, a role for gonadotropins in the functional capacity of neonata l Leydig cells is also suggested.