An assessment of inhibin-like activity secreted by Sertoli cells in culture using castrated adult male rats

Abstract

Sertoli cells isolated from testes of 16-18 days old male rats were maintained in culture. Incubation media from these culture were pooled on day 7 and tested for its inhibin-like activity either with (SCCM) or after charcoal treatment (CSCCM) in castrated adult male rats. The assay was based on the tacit assumption that SCCM or CSCCM would specifically lower circulating blood serum levels of FSH. Subcutaneous (sc)injections of CSCCM at a dose level of 1 mg protein per rat, per day, × 3 days caused a specific suppression of FSH levels, while lower dosages of CSCCM (Protein content of 300 µg or 600 μg/rat/day, × 3 days) were without any affect on basal levels of FSH and LH. SCCM was ineffective at all dose levels tested. Intracardiac injections of varying doses of LHRH (25 to 400 ng/rat) to CSCCM pre-treated rats (200 μg/rat/day, × 3 days) failed to increase the levels of LH and FSH. These results support the presence of inhibin like activity in SCCM by a bioassay procedure alternate to in vitro pituitary cell culture system used by other investigators.