Relationship between maternal plasma progesterone concentration and interferon-tau synthesis by the conceptus in cattle

• Published in: Theriogenology Vol. 47; no. 3; pp. 703 - 714
• Main Authors: Kerbler, T.L., Buhr, M.M., Jordan, L.T., Leslie, K.E., Walton, J.S.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.02.1997
• Subjects: BOVIN DE BOUCHERIE; CORPS JAUNE; CUERPO LUTEO; DESARROLLO EMBRIONARIO; DEVELOPPEMENT EMBRYONNAIRE; DIAMETRE; DIAMETRO; GANADO DE CARNE; GENISSE; GESTACION; GESTATION; GONADOTROPHINE; GONADOTROPINAS; human chorionic gonadotrophin; INJECTION; INTERFERON; interferon-τ; INTERFERONAS; INYECCION; NOVILLA; PERFORMANCE DE REPRODUCTION; PLASMA SANGUIN; PLASMA SANGUINEO; pregnancy; PROGESTERONA; PROGESTERONE; REPRODUCTIVIDAD; VACA; VACHE; interferon-τ; human chorionic gonadotrophin; progesterone; pregnancy
• ISSN: 0093-691X; 1879-3231
• DOI: 10.1016/S0093-691X(97)00028-9

The objective of this study was to determine the relationship between maternal progesterone concentration and conceptus synthesis of interferon-τ as an index of conceptus viability at the time of maternal recognition of pregnancy. Heifers of mixed beef breeds were randomly assigned to receive 1 of 2 treatments: 1) intramuscular injection of 1500 IU hCG on Day 5 after artificial insemination (AI; n = 12) or 2) intramuscular injection of saline on Day 5 after AI (n = 17). Ovaries were scanned daily by transrectal real-time ultrasonography. Progesterone concentrations were determined from daily blood samples collected from the jugular vein. Heifers were slaughtered on Day 18 after AI and conceptus tissues were collected. These were incubated individually at 37 °C in RPMI medium, and supernatant collected after 24 h. Conceptus secretory products in the supernatant were analyzed for interferon concentration by antiviral assay using vesicular stomatitis virus. Transrectal ultrasonography showed all heifers that received hCG had at least 1 extra corpus luteum (CL) in addition to the spontaneous CL formed from the previous ovulation (10 with 2 CL, 2 with 3 CL). A significant increase in plasma progesterone concentration was detected in pregnant heifers treated with hCG (n = 9) vs pregnant control heifers (n = 11; P < 0.001). There was a tendency for an increase (P = 0.059) in synthesis of interferon-τ by conceptuses from hCG-treated heifers compared to control heifers. Maternal plasma progesterone concentrations were correlated with interferon-τ production by the conceptuses (r = 0.593, P < 0.006), suggesting that higher maternal progesterone may provide a more suitable environment for the developing conceptus.