Inhibin B, Serum

Inhibin B consists of two partially homologous disulphide linked subunits, α and β. Inhibin B and A are regulated by gonadotropins and stage of follicle development. Preantral follicles exclusively secrete inhibin B, whereas both inhibin B and inhibin A are secreted from small antral follicles. Inhibin B plays a role in the regulation of FSH level. In the male, inhibin B is the main inhibin secreted by the sertoli cells of the testis. Administration of FSH in men with hypospermatogenesis increase inhibin B along with sperm number.

Along with inhibin A, inhibin B is used as a marker of follicle development, thus, inhibin B may be useful as an early indicator of response during ovarian stimulation and as a prognostic marker for women undergoing assisted reproductive techniques. In the diagnosis of malignancies, inhibin B is elevated in a majority of women with granulosa cell tumours and epithelial ovarian cancers. In males, inhibin B levels are low in most subjects with sertoli cells only syndrome and in individuals using hormonal contraceptives. It is also decreased in men treated with chemotherapy for haematological malignancy due to seminiferous tubule damage. Normal inhibin B levels in males with sertoli cells only syndrome may have focal areas of spermatogenesis, thus, increasing the possibility of extracting sperms.

1 ml Serum Frozen

Sample must be collected on 3rd day of cycle.

Male: 25-325 pg/mL Female: Normal: < 341 pg/mL Postmenopause: < 4 pg/mL 3rd day of cycle: < 273 pg/ml