Abstract
The changes in interleukin-1(IL-1)β mRNA expression and the number of macrophages were studied in the ovary during the estrous cycle in rats and after intraperitoneal injection of lipopolysaccharide (LPS, 2mg/body )2 hours before autopsy. IL-1β mRNA expression was very low in the ovary, and there was no statistically significan tchange during the estrous cycle. Hybridization signals of IL-1β mRNA were localized intensely in the thecal layer, moderately in the corpora lutea, and slightly in granulosa cells of the ovary during the cycle. The number o fmacrophages seen mainly in the hilum and interstitium significantly increased on proestrus compared with otherestrous days. LPS significantly increased IL-1β mRNA expression on each day with the highest response to LPS at 1500h on proestrus, and caused an increase in the number of macrophages in the ovary within 2 hours. These results indicate that IL-1β mRNA expressions are low during the estrous cycle in rats, and proestrus is the day of maximal IL-1β synthesis in response to LPS. The increase in IL-1β synthesis caused by LPS might be due to at least the influx of macrophages into the ovary.
