EXPRESSION OF TUMOR-NECROSIS-FACTOR-ALPHA AND ITS MESSENGER-RNA IN THE ENDOMETRIAL MUCOSA DURING THE MENSTRUAL-CYCLE

Endometrialbiopsies, collectedat various phases of the menstrual cycle , were examined for the presence of tumor necrosis factor-alpha (TVF-a lpha) by histochemistry, and TNF-alpha mRNA by in situ hybridization a nd Northern blotting. During the proliferative phase, TNF-alpha and TN F-alpha mRNA were not detected or were at low levels. During the secre tory phase, the TNF-alpha mRNA level was increased and observed in the wall of coiled arteries. TVF-alpha was detected both in the wall of t he coiled arteries and, in highest concentration, within the epithelia l cells. In regard to the capacity of TNF-alpha to induce a hemorrhagi c necrosis in various tissues, this study suggests that an over-produc tion of TNF-alpha within the small arteries of the endometrial mucosa might be responsible for menstruation.