A simple and rapid in vitro bioassay for inhibin.
This report describes a quantitative bioassay for inhibin which can be used to monitor purification and establish the physiological role of this hormone in spermatogenesis and folliculogenesis. Anterior pituitary cells from adult male Sprague-Dawley rats were dispersed and precultured for 18 h before the addition of inhibin-containing materials to the culture medium. After a further 72 h in culture, the medium was removed by aaspiration, and the cells were lysed releasing their intracellular hormone into RIA buffer. Cell content of FSH was reduced in inhibin-containing preparations, but without changes in LH, GH, and PRL concentrations. The inhibin dose-response curve, based on the inhibition of FSH in 15 experiments using an ovine testicular lymph preparation as a standard, had indices of precision between -0.032 and -0.098, and Finney's g ranged from 0.003--0.025. The interassay variability ranged from 15.0--16.9%. The assay had a practical capacity of 300--400 wells, which permitted the measurement of dose-response curves of 15 or more unknowns with quadruplicate wells per dose. The potency of unknown preparations was calculated with reference to the inhibin standard, which had a designated potency of 1 U/mg. Preparations showing nonparallelism were excluded. This assay presented advantages over those described previously, since it showed specificity of response to FSH and accommodated a large number of samples without loss of precision or reproducibility. It is therefore suitable for measurement of the inhibin-like activity in some biological fluids.
D000818:Animals; D001681:Biological Assay / Q000379:methods; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D005640:Follicle Stimulating Hormone / Q000037:antagonists & inhibitors*; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology; D006801:Humans; D007265:Inhibins; D008196:Lymph / Q000032:analysis; D008297:Male; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000378:metabolism*; D011506:Proteins / Q000032:analysis* / Q000494:pharmacology; D051381:Rats; D012756:Sheep; D013735:Testicular Hormones / Q000032:analysis* / Q000494:pharmacology; D013737:Testis / Q000032:analysis
D011506:Proteins; D013735:Testicular Hormones; D007987:Gonadotropin-Releasing Hormone; D007265:Inhibins; D005640:Follicle Stimulating Hormone