Biomaterial Database

Action of angiotensin II on the electrical and mechanical activity of rat uterine smooth muscle. 1980

J Mironneau, and C Mironneau, and A Grosset, and G Hamon, and J P Savineau

The effects of angiotensin II (A II) were studied on membrane potentials, ionic currents and isometric contractions in uterine smooth muscle strips from pregnant rats. In reference solution, A II in a low concentration (5 x 10(-9) M) exerted no effect on the resting potential or the action potential amplitude but significantly increased the rate of repetitive firing. However, in tetraethylammonium chloride (TEA)-containing solution, an increase in the action potential amplitude was always observed. The inward and outward currents were increased simultaneously, so that it was necessary to block the outward current with TEA ions in order to measure the enhancement of the inward current. The reduction of the deactivation time constants of the outward current as well as the increase in the inward current intensity could account for the acceleration of rhythmic activity in the presence of the peptide. The mechanical response to A II consisted of early tetanus which was followed by increased twitch contractions. The calcium contractures were also increased in depolarized strips. The tetanus could be dependent on the increase in and prolongation of repetitive firing while the enhancement of twitch contractions and calcium contractures could be explained by the increase in inward current intensity.

UI	MeSH Term	Description	Entries
D009215	Myometrium	The smooth muscle coat of the uterus, which forms the main mass of the organ.	Uterine Muscle,Muscle, Uterine,Muscles, Uterine,Uterine Muscles
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
D005260	Female		Females
D000200	Action Potentials	Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.	Spike Potentials,Nerve Impulses,Action Potential,Impulse, Nerve,Impulses, Nerve,Nerve Impulse,Potential, Action,Potential, Spike,Potentials, Action,Potentials, Spike,Spike Potential
D000804	Angiotensin II	An octapeptide that is a potent but labile vasoconstrictor. It is produced from angiotensin I after the removal of two amino acids at the C-terminal by ANGIOTENSIN CONVERTING ENZYME. The amino acid in position 5 varies in different species. To block VASOCONSTRICTION and HYPERTENSION effect of angiotensin II, patients are often treated with ACE INHIBITORS or with ANGIOTENSIN II TYPE 1 RECEPTOR BLOCKERS.	Angiotensin II, Ile(5)-,Angiotensin II, Val(5)-,5-L-Isoleucine Angiotensin II,ANG-(1-8)Octapeptide,Angiotensin II, Isoleucine(5)-,Angiotensin II, Valine(5)-,Angiotensin-(1-8) Octapeptide,Isoleucine(5)-Angiotensin,Isoleucyl(5)-Angiotensin II,Valyl(5)-Angiotensin II,5 L Isoleucine Angiotensin II,Angiotensin II, 5-L-Isoleucine
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
D014590	Uterine Contraction	Contraction of the UTERINE MUSCLE.	Myometrial Contraction,Contraction, Myometrial,Contraction, Uterine,Contractions, Myometrial,Contractions, Uterine,Myometrial Contractions,Uterine Contractions
D014599	Uterus	The hollow thick-walled muscular organ in the female PELVIS. It consists of the fundus which is the site of EMBRYO IMPLANTATION and FETAL DEVELOPMENT. Beyond the isthmus at the perineal end of fundus, is CERVIX UTERI (the neck) opening into VAGINA. Beyond the isthmi at the upper abdominal end of fundus, are the FALLOPIAN TUBES.	Fundus Uteri,Uteri,Uterine Cornua,Uterine Fundus,Uterus Cornua,Womb,Cornua, Uterine,Fundus Uterus,Fundus, Uterine,Uteri, Fundus,Wombs
D051381	Rats	The common name for the genus Rattus.	Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus
D066298	In Vitro Techniques	Methods to study reactions or processes taking place in an artificial environment outside the living organism.	In Vitro Test,In Vitro Testing,In Vitro Tests,In Vitro as Topic,In Vitro,In Vitro Technique,In Vitro Testings,Technique, In Vitro,Techniques, In Vitro,Test, In Vitro,Testing, In Vitro,Testings, In Vitro,Tests, In Vitro,Vitro Testing, In