Follicle-stimulating hormone-testosterone interaction in modulating steroidogenesis in bovine granulosa cells. I. Effect on progesterone production.
The aim of this study was to investigate the effects of testosterone on basal and follicle-stimulating hormone (FSH)-induced progesterone production by cultured bovine granulosa cells. Granulosa cells were isolated from small (< 5 mm) and large (> 8 mm) follicles and cultured for 48 h in 1 ml of Medium-199 with different concentrations of FSH (0.1, 1, 10 and 35 mg/l). In addition, the combined effects of different amounts of testosterone (1 nmol-10 mumol) and 1 mg/l FSH for 48 h on progesterone production by granulosa cells of both groups of follicles were studied; progesterone production during the subsequent 24-h incubation period was evaluated in the absence of hormones. In a third experiment, granulosa cells were treated with 500 micrograms of dibutyryl-cAMP and 10 mumol of testosterone for 48 h. At the end of each incubation period, the progesterone content in the culture media was determined by a validated radioimmunoassay. Basal progesterone release during the 48-h incubation period was higher in granulosa cells from small as compared to cells from large follicles; in both groups of cells, progesterone production was stimulated maximally by 1 mg/l FSH. The treatment with 10 mumol of testosterone induced a decrease of progesterone production in both groups of cells, while lower amounts exerted an inhibitory effect only in cells from large follicles. Furthermore, 10 mumol of testosterone inhibited FSH-induced progesterone release, while lower dosages were ineffective. Dibutyryl-cAMP stimulated significantly the progesterone output by granulosa cells of both groups and testosterone was effective in suppressing this increase.(ABSTRACT TRUNCATED AT 250 WORDS)
Grasselli
F
F
Istituto di Fisiologia Veterinaria, Università di Parma, Italy.
Basini
G
G
Bussolati
S
S
Tamanini
C
C
D000818:Animals; D003994:Bucladesine / Q000008:administration & dosage; D002417:Cattle; D000242:Cyclic AMP / Q000096:biosynthesis; D004347:Drug Interactions; D005260:Female; D005640:Follicle Stimulating Hormone / Q000008:administration & dosage*; D006107:Granulosa Cells / Q000187:drug effects* / Q000378:metabolism*; D066298:In Vitro Techniques; D011374:Progesterone / Q000096:biosynthesis*; D013739:Testosterone / Q000008:administration & dosage*
D013739:Testosterone; D011374:Progesterone; D003994:Bucladesine; D005640:Follicle Stimulating Hormone; D000242:Cyclic AMP