Biomaterial Database

Inhibition of the tocolytic activity of atrial natriuretic factor by progesterone and potentiation by progesterone receptor antagonist RU486 in rats. 1991

W Potvin, and S Mulay, and D R Varma

Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada.

1. The influence of progesterone on the activity of atrial natriuretic factor (ANF) on rat myometrial motor activity was determined in vitro. 2. ANF inhibited the tension development by myometrium from cycling or oestrogen-treated rats in a dose-dependent manner; maximal inhibition was 100%. 3. Injections of progesterone into rats inhibited the tocolytic activity of ANF in a dose and time-dependent manner. The tocolytic effects of ANF were completely abolished by 3 daily injections of 1 mg kg-1 progesterone. 4. Pregnancy-related increase in plasma progesterone was accompanied by a corresponding decrease in the tocolytic effects of ANF; myometria from gestational day 10 to 21 were completely refractory and those from earlier gestational age and immediate postpartum were responsive to ANF to varying degrees. 5. Treatment of pregnant rats with the progesterone antagonist, RU486, caused abortions and vaginal bleeding, decreased plasma progesterone concentrations and restored the tocolytic activity of ANF. Tocolytic activity of ANF on virgin rat myometria was potentiated by RU486. 6. Progesterone also inhibited the effects of ANF on myometria from ovariectomized rats. 7. Tocolytic activity of isoprenaline was not modified by progesterone, pregnancy, RU486 or ovariectomy. 8. It is concluded that progesterone antagonizes myometrial effects of ANF by an oestrogen-independent mechanism and the pregnancy-induced refractoriness to the tocolytic effects of ANF is caused by progesterone.

UI	MeSH Term	Description	Entries
D009320	Atrial Natriuretic Factor	A potent natriuretic and vasodilatory peptide or mixture of different-sized low molecular weight PEPTIDES derived from a common precursor and secreted mainly by the HEART ATRIUM. All these peptides share a sequence of about 20 AMINO ACIDS.	ANF,ANP,Atrial Natriuretic Peptide,Atrial Natriuretic Peptides,Atriopeptins,Auriculin,Natriuretic Peptides, Atrial,ANF (1-126),ANF (1-28),ANF (99-126),ANF Precursors,ANP (1-126),ANP (1-28),ANP Prohormone (99-126),ANP-(99-126),Atrial Natriuretic Factor (1-126),Atrial Natriuretic Factor (1-28),Atrial Natriuretic Factor (99-126),Atrial Natriuretic Factor Precursors,Atrial Natriuretic Factor Prohormone,Atrial Natriuretic Peptide (1-126),Atrial Pronatriodilatin,Atriopeptigen,Atriopeptin (1-28),Atriopeptin (99-126),Atriopeptin 126,Atriopeptin Prohormone (1-126),Cardiodilatin (99-126),Cardiodilatin Precursor,Cardionatrin I,Cardionatrin IV,Prepro-ANP,Prepro-CDD-ANF,Prepro-Cardiodilatin-Atrial Natriuretic Factor,Pro-ANF,ProANF,Proatrial Natriuretic Factor,Pronatriodilatin,alpha ANP,alpha-ANP Dimer,alpha-Atrial Natriuretic Peptide,beta-ANP,beta-Atrial Natriuretic Peptide,gamma ANP (99-126),gamma-Atrial Natriuretic Peptide,Natriuretic Peptide, Atrial,Peptide, Atrial Natriuretic,Peptides, Atrial Natriuretic,Prepro ANP,Prepro CDD ANF,Prepro Cardiodilatin Atrial Natriuretic Factor,Pro ANF,alpha ANP Dimer,alpha Atrial Natriuretic Peptide,beta ANP,beta Atrial Natriuretic Peptide,gamma Atrial Natriuretic Peptide
D010053	Ovary	The reproductive organ (GONADS) in female animals. In vertebrates, the ovary contains two functional parts: the OVARIAN FOLLICLE for the production of female germ cells (OOGENESIS); and the endocrine cells (GRANULOSA CELLS; THECA CELLS; and LUTEAL CELLS) for the production of ESTROGENS and PROGESTERONE.	Ovaries
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
D011919	Rats, Inbred Strains	Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.	August Rats,Inbred Rat Strains,Inbred Strain of Rat,Inbred Strain of Rats,Inbred Strains of Rats,Rat, Inbred Strain,August Rat,Inbred Rat Strain,Inbred Strain Rat,Inbred Strain Rats,Inbred Strains Rat,Inbred Strains Rats,Rat Inbred Strain,Rat Inbred Strains,Rat Strain, Inbred,Rat Strains, Inbred,Rat, August,Rat, Inbred Strains,Rats Inbred Strain,Rats Inbred Strains,Rats, August,Rats, Inbred Strain,Strain Rat, Inbred,Strain Rats, Inbred,Strain, Inbred Rat,Strains, Inbred Rat
D011980	Receptors, Progesterone	Specific proteins found in or on cells of progesterone target tissues that specifically combine with progesterone. The cytosol progesterone-receptor complex then associates with the nucleic acids to initiate protein synthesis. There are two kinds of progesterone receptors, A and B. Both are induced by estrogen and have short half-lives.	Progesterone Receptors,Progestin Receptor,Progestin Receptors,Receptor, Progesterone,Receptors, Progestin,Progesterone Receptor,Receptor, Progestin
D004357	Drug Synergism	The action of a drug in promoting or enhancing the effectiveness of another drug.	Drug Potentiation,Drug Augmentation,Augmentation, Drug,Augmentations, Drug,Drug Augmentations,Drug Potentiations,Drug Synergisms,Potentiation, Drug,Potentiations, Drug,Synergism, Drug,Synergisms, Drug
D004971	Estrus	The period in the ESTROUS CYCLE associated with maximum sexual receptivity and fertility in non-primate female mammals.
D005260	Female		Females
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