Supplementation of progesterone (P₄) in pregnant gilts increases concentrations of circulating P₄ and stimulates the secretory activity of the endometrium. In this study, there was examination of the consequences of exogenous P₄ administration on luteal P₄ content and the expression of genes related to the corpus luteum (CL) function. Gilts with gonadotropin-induced estrus were administered daily injections of corn oil (n = 8) or P₄ (n = 8) on days 3 through 10 after insemination. The animals were slaughtered on day 12 of pregnancy to obtain corpora lutea for real-time polymerase chain reaction analyses of selected genes and for enzyme immunoassay of P₄. Injections with P₄ had no effect on the concentration of P₄ and the relative abundance of mRNA transcripts of cholesterol transport-related proteins, steroidogenic enzymes, and receptors for luteotropic factors in the luteal tissue. The abundance of prostaglandin (PG) endoperoxide synthase 2, PGI2 synthase, PGI2 receptor, fibroblast growth factor 2, peroxisome proliferator-activated receptor γ, and tumor necrosis factor α receptor type I transcripts increased after P₄ treatment. In contrast, the relative abundance of angiopoietin 2 mRNA decreased in response to P₄ administration. In summary, P₄ supplementation in pregnant gilts does not affect luteal steroidogenesis but modulates the abundance of factors related to vascular function. Given that the endometrium is the main target tissue for P₄, an indirect uterine-mediated effect of exogenous P₄ on CL function is likely.

在怀孕的小母猪中补充黄体酮 (P ₄ ) 会增加循环 P _{4 的}浓度并刺激子宫内膜的分泌活动。在这项研究中，检查了外源性 P ₄给药对黄体 P ₄含量和与黄体 (CL) 功能相关基因表达的影响。 在受精后第 3 天至第 10 天，对具有促性腺激素诱导发情的小母猪每天注射玉米油 ( n  = 8) 或 P ₄ ( n = 8)。在妊娠第 12 天屠宰动物以获得黄体，用于选定基因的实时聚合酶链反应分析和 P₄ . 有P注射₄对P的浓度没有影响₄和胆固醇转运相关的蛋白质，类固醇合成酶，和受体的mRNA转录物的相对丰度在黄体组织黄体生成的因素。P ₄治疗后，前列腺素 (PG) 内过氧化物合酶 2、PGI2 合酶、PGI2 受体、成纤维细胞生长因子 2、过氧化物酶体增殖物激活受体 γ 和肿瘤坏死因子 α 受体 I 型转录物的丰度增加。相比之下，血管生成素 2 mRNA 的相对丰度响应于 P ₄给药而降低。总之，P ₄妊娠小母猪的补充剂不会影响黄体类固醇的生成，但会调节与血管功能相关的因素的丰度。鉴于子宫内膜是 P ₄的主要靶组织，外源性 P ₄对 CL 功能的间接子宫介导的影响是可能的。