Tumour necrosis factor-α differentially alters progesterone and prostaglandin F2α production by porcine luteal cells

Abstract

Abstract This study examined the effects of tumour necrosis factor-α (TNFα) on basal and stimulated progesterone secretion, as well as prostaglandin F2α production, by small, large and mixed porcine luteal cells and assessed the action of TNFα in the presence and absence of indomethacin. Corpora lutea were isolated from gilts on days 8–9 of the oestrous cycle and enzymatically dissociated. Luteal cells were either subjected to elutriation to isolate small and large cells or were separated from erythrocytes by a polysucrose gradient to serve as the mixed luteal cell group. Then 24-well culture plates were seeded with 150 000 small, 30 000 large and mixed (30 000 large+100 000-250 000 small) luteal cells suspended in 1 ml medium 199 media supplemented with 5 μg insulin/ml, 40 ng cortisol/ml and 50 μg low-density lipoproteins/ml. Cells were cultured for up to 24 h in a humidified incubator at 37 °C with 5% CO2 in air. TNFα time- and dose-dependently suppressed (P<0·05) LH-induced, but not basal, progesterone secretion by small luteal cells. Moreover, TNFα inhibited (P<0·05) forskolin-mediated, but not cyclic AMP-mediated, progesterone secretion by small luteal cells. The LH-stimulated progesterone secretion by small luteal cells was not affected by TNFα in the presence of indomethacin. Progesterone secretion by large and mixed luteal cells was not affected by TNFα. Prostaglandin F2α production by small and mixed, but not large, luteal cells was enhanced (P<0·05) by TNFα. These data demonstrated that TNFα acts primarily on a target cell(s) in the small cell fraction, and the cytokine-induced inhibition of LH-stimulated progesterone secretion by small cells was mediated by prostaglandin F2α and involved a site(s) proximal, but not distal, to cyclic AMP generation. Journal of Endocrinology (1994) 143, 75–83