Problem: Around the time of ovulation the number of neutrophils increases in the theca of the leading follicle. We hypothesized that growth-regulated alpha (GRO alpha), a neutrophil chemoat-tractant/activating factor, may be a modulator of periovulatory neutrophil chemotaxis.
Method: GRO alpha levels were measured in follicular fluids (n = 61). Granulosa-lutein and ovarian stromal cells were also cultured. After experimental paradigms, GRO alpha mRNA was evaluated by Northern analysis, GRO alpha in follicular fluids, and culture supernatants were quantified using ELISA.
Results: In follicular fluids the mean pre-human chorionic gonadotropin (hCG) GRO alpha level was 51 +/- 24 (+/- SEM) pg/ml, post-hCG it was 210 +/- 20 pg/ml (P = 0.04). GRO was produced constitutively by ovarian stromal and granulosa-lutein cells. Interleukin-alpha (IL-1 alpha) and tumor necrosis factor-alpha (TNF-alpha) further stimulated GRO alpha production. Treatment of stromal cells with hCG also stimulated GRO alpha production.
Conclusion: GRO alpha is a constituent of periovulatory follicular fluid. Ovarian stromal and granulosa-lutein cells express the GRO alpha mRNA and produce the protein. The regulation of GRO alpha by cytokines and hCG suggests that GRO alpha may play a role in the process of ovulation.