Responses of porcine corpora lutea to somatotropin administration during pregnancy

• Published in: Journal of animal science Vol. 74; no. 4; pp. 873 - 878
• Main Authors: Yuan, W. (University of Missouri, Columbia.), Sterle, J.A, Cantley, T.C, Lamberson, W.R, Day, B.N, Lucy, M.C
• Format: Journal Article
• Language: English
• Published: Savoy, IL Am Soc Animal Sci 01-04-1996; American Society of Animal Science; Oxford University Press
• Subjects: 3-Hydroxysteroid Dehydrogenases - analysis; 3-Hydroxysteroid Dehydrogenases - genetics; 3-Hydroxysteroid Dehydrogenases - metabolism; Animals; ARN MENSAJERO; ARN MESSAGER; Biological and medical sciences; Cattle; CERDAS; Cholesterol Side-Chain Cleavage Enzyme - analysis; Cholesterol Side-Chain Cleavage Enzyme - genetics; Cholesterol Side-Chain Cleavage Enzyme - metabolism; CORPS JAUNE; Corpus Luteum - metabolism; Corpus Luteum - physiology; CUERPO LUTEO; ENZIMAS; ENZYME; Female; FOIE; Follicle Stimulating Hormone - analysis; Follicle Stimulating Hormone - genetics; Follicle Stimulating Hormone - metabolism; FSH; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation; Gene Expression Regulation, Enzymologic; GESTACION; GESTATION; Growth Hormone - pharmacology; HFS; HIGADO; Hogs; Hormone metabolism and regulation; Hormones; Liver - chemistry; Liver - metabolism; Liver - physiology; OVAIRE; OVARIOS; Ovary - chemistry; Ovary - metabolism; Ovary - physiology; OXIDORREDUCTASAS; OXYDOREDUCTASE; PLASMA SANGUIN; PLASMA SANGUINEO; Pregnancy; Pregnancy, Animal - metabolism; Pregnancy, Animal - physiology; Pregnancy. Parturition. Lactation; PROGESTERONA; PROGESTERONE; Progesterone - blood; RECEPTEUR D'HORMONE; RECEPTORES DE HORMONAS; Receptors, LH - analysis; Receptors, LH - genetics; Receptors, LH - metabolism; Receptors, Somatotropin - analysis; Receptors, Somatotropin - genetics; Receptors, Somatotropin - metabolism; Recombinant Proteins - pharmacology; RNA, Messenger - analysis; RNA, Messenger - genetics; SOMATOTROPINA; SOMATOTROPINE; Swine - metabolism; Swine - physiology; TRUIE; Vertebrates: reproduction; STH; Gonadotropin; Gene expression; Ovarian hormone; Pig; Pregnancy; Ovary; Vertebrata; Mammalia; Adenohypophyseal hormone; Female genital system; Corpus luteum; Steroidogenesis; Artiodactyla; Progesterone; Sex steroid hormone; LH; Ungulata; Hormonal receptor
• ISSN: 0021-8812; 1525-3163; 0021-8812
• DOI: 10.2527/1996.744873x

The effects of somatotropin (ST) on functions of porcine corpora lutea (CL) during pregnancy were investigated. Twenty-four crossbred (Yorkshire/Landrace) gilts from d 30 to 43 of pregnancy were injected daily with 5 mg of recombinant porcine somatotropin (rpST; n = 12) or 1 mL of saline (control, n = 12). Blood was collected on d 30, 37, and 43 for analyses of plasma progesterone. Gilts were killed on d 44 of pregnancy, and mRNA were isolated from CL, ovary, and liver. Messenger RNA expression for LH receptor, FSH receptor, ST receptor, 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD), and cytochrome P450 side-chain cleavage enzyme (SCC) were measured. Liver, CL, and ovary contained a 4.7-kb mRNA of ST receptor, but the liver contained more mRNA for ST receptor than did CL or ovary (.97 +/- 0.18, 0.47 +/- 0.04, and 0.25 +/- 0.04 units, respectively). There were two variants of LH receptor mRNA in CL (6.8 and 4.4 kb). The CL also contained a 1.8-kb mRNA of SCC and a 1.7-kb mRNA of 3 beta-HSD. No FSH receptor mRNA was detected in CL of the pig. The rpST treatment did not affect the mRNA level of ST receptor, 3 beta-HSD, SCC, or 4.4-kb mRNA of the LH receptor. The 6.8-kb mRNA for the LH receptor was decreased (P 0.05) by rpST (.56 +/- 0.04 vs 0.78 +/- 0.05 units). Furthermore, concentrations of plasma progesterone decreased (P 0.001) in gilts treated with rpST. Decreased luteal function was associated with decreased expression of LH receptor in rpST-treated gilts. The luteotropic effects of ST observed in vitro do not necessarily occur in vivo when gilts are administered rpST during pregnancy