Changes in interleukin-1 production of peritoneal macrophages during estrous cycle in golden hamsters.

The present study demonstrated the change in interleukin-1 (IL-1) production of peritoneal macrophages during the estrous cycle in golden hamsters and discussed its possible roles in ovarian function. Macrophages were collected from the peritoneal cavity at 0900 h on various days of the estrous cycle and incubated for 6 h in the presence of ovine pituitary LH (500 ng/ml). The IL-1 concentration in the media was measured by bioassay with the A375S2 human melanoma cell line. The number of macrophages significantly (P < 0.01) increased on estrus and proestrus compared with diestrus 1 or diestrus 2. LH-induced production of IL-1 was also greater (P < 0.01) on proestrus (292 +/- 36 pg/10(6) cells/ ml) and estrus (222 +/- 30 pg/10(6) cells/ml) than on diestrus 1 (34 +/- 15 pg/10(6) cells/ml) or diestrus 2 (117 +/- 16 pg/10(6) cells/ml). To clarify the factor inducing the changes in peritoneal macrophages, hamsters were ovariectomized on diestrus 1, and 3 weeks later the animals were treated with s.c. injections of progesterone (200 micrograms/day), testosterone (100 micrograms/day), estradiol (10 micrograms/day) or sesame oil for three days. The hamsters were killed 24 h after the last injection, and the number and IL-1 producing capacity of macrophages were determined. The number of macrophages and their response to LH to produce IL-1 were increased significantly (P < 0.01) by estradiol treatment but not by progesterone or testosterone treatment. It was concluded that the peritoneal macrophages became more sensitive to LH to produce IL-1 on proestrus and estrus in cyclic hamsters, and that these changes in macrophages, probably induced by estradiol, would play important roles in ovarian function.