Interleukin-1 in human ovarian cells and in peripheral blood monocytes increases during the luteal phase: evidence for a midcycle surge in the human

Abstract

Objective: Resident ovarian macrophages are thought to be critically involved in cyclic ovarian events. A prominent macrophage product, interleukin-1, has been shown to affect ovarian cell function. In this report we present evidence for an intrafollicular periovulatory interleukin-1 surge. Additionally, we demonstrate that interleukin-1 beta messenger ribonucleic acid in peripheral blood monocytes increases threefold during the luteal phase of the menstrual cycle over that found in the follicular phase.

Study design: Follicular fluid cells isolated as a byproduct of transvaginal oocyte retrievals in gonadotropin-stimulated in vitro fertilization cycles were immunoprobed for the presence of interleukin-1 protein. Late follicular phase cumulus and granulosa cells obtained from an aspirated preovulatory follicle were likewise probed.

Results: Although the in vitro fertilization-retrieved cells stained positive for interleukin-1 protein, the late follicular phase cells were devoid of the protein. Granulosa cells from in vitro fertilization cycles were examined for interleukin-1 protein binding sites with iodinated interleukin-1 alpha protein. These cells were found to have approximately 2000 binding sites per cell. Poly A+ messenger ribonucleic acid isolated from peripheral blood monocyte samples from women during the follicular and luteal phases and from male controls were probed for interleukin-1 ribonucleic acid content by means of Northern analysis. The luteal samples contained a threefold higher interleukin-1 messenger ribonucleic acid content that did the follicular phase samples or the controls.

Conclusion: The ovarian interleukin-1 protein increase taken together with increased peripheral blood monocyte interleukin-1 messenger ribonucleic acid suggests that interleukin-1 production increases at midcycle.