Biomaterial Database

Effect of progesterone withdrawal in sheep during late pregnancy. 1982

M J Taylor, and R Webb, and M D Mitchell, and J S Robinson

The concentration of progesterone in the peripheral plasma of seven sheep during late pregnancy was reduced by injection of an inhibitor of 3 beta-hydroxysteroid dehydrogenase activity. Concentrations of progesterone were 10.0 +/- 1.0 (S.E.M) ng/ml (n = 6) before injection of the inhibitor, fell to 1.39 +/- 0.40 ng/ml (n = 6) 30 min after injection, and remained within this lowered range for 6 h after injection. By 20-24h and 30-35h after injection progesterone concentrations had recovered to 4.63 +/- 0.94 and 14.07 +/-4.17 ng/ml respectively (n = 6). Six out of seven ewes delivered prematurely 32.5 +/- 2.9h after injection. Delivery appeared to be normal, and was associated with increasing concentrations of 13, 14-dihydro-15-oxo prostaglandin F2 alpha in peripheral plasma. Concentrations of oestradiol-17 beta in peripheral plasma were slightly raised immediately before delivery, at which time progesterone concentrations were within the preinjection range. These data suggest that progesterone withdrawal is one mechanism that initiates increased prostaglandin F2 alpha secretion in the pregnant sheep.

UI	MeSH Term	Description	Entries
D007743	Labor, Obstetric	The repetitive uterine contraction during childbirth which is associated with the progressive dilation of the uterine cervix (CERVIX UTERI). Successful labor results in the expulsion of the FETUS and PLACENTA. Obstetric labor can be spontaneous or induced (LABOR, INDUCED).	Obstetric Labor
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D011374	Progesterone	The major progestational steroid that is secreted primarily by the CORPUS LUTEUM and the PLACENTA. Progesterone acts on the UTERUS, the MAMMARY GLANDS and the BRAIN. It is required in EMBRYO IMPLANTATION; PREGNANCY maintenance, and the development of mammary tissue for MILK production. Progesterone, converted from PREGNENOLONE, also serves as an intermediate in the biosynthesis of GONADAL STEROID HORMONES and adrenal CORTICOSTEROIDS.	Pregnenedione,Progesterone, (13 alpha,17 alpha)-(+-)-Isomer,Progesterone, (17 alpha)-Isomer,Progesterone, (9 beta,10 alpha)-Isomer
D011460	Prostaglandins F	(9 alpha,11 alpha,13E,15S)-9,11,15-Trihydroxyprost-13-en-1-oic acid (PGF(1 alpha)); (5Z,9 alpha,11,alpha,13E,15S)-9,11,15-trihydroxyprosta-5,13-dien-1-oic acid (PGF(2 alpha)); (5Z,9 alpha,11 alpha,13E,15S,17Z)-9,11,15-trihydroxyprosta-5,13,17-trien-1-oic acid (PGF(3 alpha)). A family of prostaglandins that includes three of the six naturally occurring prostaglandins. All naturally occurring PGF have an alpha configuration at the 9-carbon position. They stimulate uterine and bronchial smooth muscle and are often used as oxytocics.	PGF
D011863	Radioimmunoassay	Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.	Radioimmunoassays
D005260	Female		Females
D000019	Abortifacient Agents	Chemical substances that interrupt pregnancy after implantation.	Abortifacient Effect,Abortifacient Effects,Abortifacients,Contraceptive Agents, Postconception,Agents, Abortifacient,Agents, Postconception Contraceptive,Effect, Abortifacient,Effects, Abortifacient,Postconception Contraceptive Agents
D000021	Abortifacient Agents, Steroidal	Steroidal compounds with abortifacient activity.	Steroid Abortifacients,Abortifacients, Steroid,Agents, Steroidal Abortifacient,Steroidal Abortifacient Agents
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012756	Sheep	Any of the ruminant mammals with curved horns in the genus Ovis, family Bovidae. They possess lachrymal grooves and interdigital glands, which are absent in GOATS.	Ovis,Sheep, Dall,Dall Sheep,Ovis dalli