TUMOR-NECROSIS-FACTOR-ALPHA RECEPTOR P55 IS UNDER HORMONAL (FOLLICLE-STIMULATING-HORMONE) CONTROL IN TESTICULAR SERTOLI CELLS

Identification of TNF alpha receptors and their regulation by the endo crine system were examined in testicular Sertoli cells. By using cross -linking experiments as well as northern blotting analysis, we detecte d the p55 receptor type (MW: 55 kDa, mRNA: 2.3 kb), but not the p75 TN F alpha receptor type. Furthermore, we report that Sertoli cell TNF al pha receptors are under the control of FSH, but not of other hormones which affect Sertoli cell activity. FSH enhances (ED(50): 2 ng/ml) TNF alpha binding to Sertoli cells. This stimulating effect of FSH occurs at the level of p55 TNF alpha receptor, as indicated by the increase in p55 mRNA after FSH treatment. Together, these observations show tha t the action of TNF alpha (which originates in the testis from germ ce lls and/or interstitial macrophages) on Sertoli cells remains under th e control of the endocrine system as shown by the regulatory effect of FSH on TNF alpha p55 receptors. (C) 1996 Academic Press, Inc.