Levels of rat testicular interleukin-1-like factor (tIL-1) have been shown to correlate with DNA synthetic activity during the cycle of the rat seminiferous epithelium, suggesting its role as a spermatogonial or meiotic growth factor. To explore this further, a new in vitro model system was developed. Rat seminiferous tubule segments from stages I, V, VIIa, and VIII-IX of the cycle were isolated by transillumination-assisted microdissection, cultured in chemically defined serum-free medium supplemented with human recombinant IL-1 alpha, and labeled with [3H]thymidine. During incubation, spontaneous progression of spermatogenesis was noted. Inactive stage VIIa tubule segments differentiated to stage VIII and initiated DNA synthesis, and concomitantly started to secrete IL-1-like factor. DNA synthesis of stages VIII-IX ceased through differentiation of spermatocytes to leptotene-zygotene (stages XII-XIII of the cycle). IL-1 alpha stimulated DNA synthesis significantly in spermatogonia of stage I. Meiotic DNA synthesis at stage VIIa was stimulated (48 h/34 C) and maintained at stages VIII-IX (48 h/34 C). IL-1 alpha seems to act as a regulator of spermatogenic DNA synthesis in both mitotic and meiotic phases. It has mainly stimulating and maintaining effects, but it may also be inhibitory under certain conditions.

Fertilization and oocyte cleavage rates have previously been demonstrated to be lower for women with endometriosis undergoing IVF compared with controls. This might be related to impaired oocyte function, possibly due to an inflammatory milieu in the pelvis of these women, where an elevated concentration of many cytokines is documented. The aim of this study was to examine whether granulosa cells from women with endometriosis deviated with respect to production of the inflammatory cytokines interleukin-1beta, interleukin-6, interleukin-8 and tumour necrosis factor alpha (TNFalpha) compared with granulosa cells from healthy women, undergoing IVF for male infertility. The effect of human chorionic gonadotrophin on cytokine production was also investigated. Granulosa cells in follicular fluid were obtained at oocyte retrieval for IVF. Incubated cell culture media were analysed by enzyme-linked immunosorbent assay. The basal production of all four cytokines was higher in cells from women with endometriosis when compared to controls, although the increase was only significant for TNFalpha. Chorionic gonadotrophin had no significant effect, although it had a tendency to suppress cytokine release in both patient categories. Whether aberrant cytokine production in granulosa cells from women with endometriosis may disturb fertilizing capacity of oocytes requires study.

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