Tumor necrosis factor-α and its receptor in the corpus luteum of pregnant cows

The objective of this study was to investigate the presence of tumor necrosis factor (TNF)-α mRNA and TNF-α receptors in the bovine corpus luteum (CL) during the gestation period. TNF-α mRNA and TNF-α receptors were determined on bovine CL from pregnant cows at three stages: trimester I (fetal crown-rum p length; 6-20 cm), trimester II (25-45 cm) and trimester (50-80 cm). TNF-α mRNA was detected by an RT-PCR analysis in the CL of all stages of gestation. A Scatchard analysis revealed the presence of a high- affinity binding site (Kd; 5.1-6.9 nM) in the CL membranes collected at each stage of gestation. Furthermore, the concentrations of TNF-α receptors in the CL of trimesters I (24.0 ± 1.95 pmol/mg protein) and III (21.6 ± 2.39 pmol/mg protein) of gestation were significantly higher than the concentration in trimester II (14.9 ± 2.07 pmol/mg protein) (P < 0.05). These results indicate that TNF-α is locally produced and that TNF-α receptors are present in bovine CL during the gestation period, and suggest that TNF-α plays one or more roles as a paracrine factor in regulating bovine CL function during the entire gestation period. (C) 2000 Wiley-Liss, Inc.