title: Tumor necrosis factor-alpha and its receptor in bovine corpus luteum throughout the estrous cycle.
abstract: The objective of this study was to investigate tumor necrosis factor alpha (TNF-alpha) expression, the presence of functional TNF-alpha receptors, and expression of TNF receptor type I (TNF-RI) mRNA in the bovine corpus luteum (CL) during different stages of the estrous cycle. Reverse transcription (RT)-polymerase chain reaction (PCR) showed no difference in TNF-alpha mRNA expression during the estrous cycle. Concentrations of TNF-alpha in the CL tissue increased significantly from the mid to the late luteal stage and decreased thereafter (P < 0.05). An RT-PCR analysis showed higher levels of TNF-RI mRNA in CL of Days 3-7 than of other stages (P < 0.05). (125)I-TNF-alpha binding to the membranes of bovine CL was maximal after incubation at 38 degrees C for 48 h. The binding was much greater for TNF-alpha than for related peptides. A Scatchard analysis revealed the presence of a high-affinity binding site in the CL membranes collected at each phase of the estrous cycle (dissociation constant: 3.60 +/- 0.58-5.79 +/- 0.19 nM). In contrast to TNF-RI mRNA expression, the levels of receptor protein were similar at each stage of the estrous cycle. When cultured cells of all luteal stages were exposed to TNF-alpha (1-100 ng/ml), TNF-alpha stimulated prostaglandin F(2alpha) and prostaglandin E(2) secretion by the cells in a dose-dependent fashion (P < 0.01), especially during the early luteal phase, although it did not affect progesterone secretion. These results indicate the local production of TNF-alpha and the presence of functional TNF-RI in bovine CL throughout the estrous cycle, and suggest that TNF-alpha plays some roles in regulating bovine CL function throughout the estrous cycle.
authors.affiliation: Laboratory of Reproductive Endocrinology, Faculty of Agriculture, Okayama University, Okayama 700-8530, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Sakumoto
authors.forename: B
authors.initials: B
authors.lastname: Berisha
authors.forename: N
authors.initials: N
authors.lastname: Kawate
authors.forename: D
authors.initials: D
authors.lastname: Schams
authors.forename: K
authors.initials: K
authors.lastname: Okuda
mesh_terms: D000818:Animals; D002417:Cattle / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D003338:Corpus Luteum / Q000378:metabolism*; D015237:Dinoprost / Q000378:metabolism; D015232:Dinoprostone / Q000378:metabolism; D004971:Estrus / Q000502:physiology*; D005260:Female; D015870:Gene Expression; D011374:Progesterone / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D018124:Receptors, Tumor Necrosis Factor / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology
chemical_list: D012333:RNA, Messenger; D018124:Receptors, Tumor Necrosis Factor; D014409:Tumor Necrosis Factor-alpha; D011374:Progesterone; D015237:Dinoprost; D015232:Dinoprostone