Myometrial tumor necrosis factor alpha: cellular localization and regulation by estradiol and progesterone in the...

The expression of tumor necrosis factor alpha (TNF) protein in mouse myometrial cells on each day of the estrous cycle and after ovariectomy, with and without replacement of estradiol (E2), progesterone (P4), or E2 + P4, was investigated. TNF protein was assessed by immunocytochemistry. In addition, the numbers of mast cells and the numbers of TNF-containing mast cells were determined under each condition. The total number of mast cells fluctuated during the estrous cycle; and at each stage, essentially 100% of the mast cells exhibited TNF immunoreactivity. In contrast, after ovariectomy and after ovariectomy with E2 replacement, only approximately 50% of the mast cells contained immunoreactive TNF. P4 treatment resulted in further decline in mast cell TNF whereby after 24 h of P4, only 3% of the mast cells were TNF-positive and by 72 h of treatment, no TNF-positive mast cells could be detected E2 and P4 in combination increased the total number of mast cells, and in a pattern reminiscent of normal cycling myometrium, over 90% of the mast cells exhibited TNF immunoreactivity after 24 h of treatment. TNF protein was detectable in muscle cells throughout the estrous cycle, with weak immunostaining observed on proestrus and more intense immunostaining on estrus, diestrus-I, and diestrus-II. After ovariectomy, only light immunostaining was observed in the muscle cells. Immunoreactive TNF was detected in muscle cells after each type of steroid treatment. E2 and E2 + P4 treatments resulted in a biphasic pattern of immunoreactive TNF expression.(ABSTRACT TRUNCATED AT 250 WORDS)