Biomaterial Database

Placental nitric oxide synthase activity and abnormal umbilical artery flow velocity waveforms. 1997

W Giles, and S O'Callaghan, and M Read, and N Gude, and R King, and S Brennecke

Discipline of Reproductive Medicine, School of Medicine and Health Sciences, University of Newcastle, Callaghan, Australia.

OBJECTIVE To assess the nitric oxide synthase activity in placentas from women with either normal or abnormal Doppler ultrasound umbilical artery flow velocity wave-forms who delivered by elective cesarean. METHODS This prospective observational study involved 16 women admitted either for elective cesarean for standard obstetric indications (with normal umbilical artery Doppler waveform studies, n = 8) or with evidence of fetal or maternal complications of pregnancy (with abnormal umbilical artery Doppler studies, n = 8). Placental tissue was collected and frozen in liquid nitrogen immediately upon delivery. Following storage at -80C, nitric oxide synthase activity was analyzed by measuring the conversion of [3H]L-arginine to [3H]L-citrulline. RESULTS Placentas from women with abnormal umbilical artery flow velocity waveforms showed significantly lower mean nitric oxide synthase activity than did placentas from women with normal umbilical artery flow velocity wave-forms (Vmax = 11.3 pmol/minute/mg protein versus 22.6 pmol/minute/mg protein). CONCLUSIONS There is a statistically significant reduction in nitric oxide synthase activity in placentas from pregnancies with abnormal umbilical artery flow velocity waveforms.

UI	MeSH Term	Description	Entries
D010920	Placenta	A highly vascularized mammalian fetal-maternal organ and major site of transport of oxygen, nutrients, and fetal waste products. It includes a fetal portion (CHORIONIC VILLI) derived from TROPHOBLASTS and a maternal portion (DECIDUA) derived from the uterine ENDOMETRIUM. The placenta produces an array of steroid, protein and peptide hormones (PLACENTAL HORMONES).	Placentoma, Normal,Placentome,Placentas,Placentomes
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
D011446	Prospective Studies	Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.	Prospective Study,Studies, Prospective,Study, Prospective
D001783	Blood Flow Velocity	A value equal to the total volume flow divided by the cross-sectional area of the vascular bed.	Blood Flow Velocities,Flow Velocities, Blood,Flow Velocity, Blood,Velocities, Blood Flow,Velocity, Blood Flow
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D014469	Umbilical Arteries	Specialized arterial vessels in the umbilical cord. They carry waste and deoxygenated blood from the FETUS to the mother via the PLACENTA. In humans, there are usually two umbilical arteries but sometimes one.	Arteries, Umbilical,Artery, Umbilical,Umbilical Artery
D016216	Ultrasonography, Prenatal	The visualization of tissues during pregnancy through recording of the echoes of ultrasonic waves directed into the body. The procedure may be applied with reference to the mother or the fetus and with reference to organs or the detection of maternal or fetal disease.	Fetal Ultrasonography,Prenatal Diagnosis, Ultrasonic,Ultrasonography, Fetal,Diagnosis, Prenatal Ultrasonic,Diagnosis, Ultrasonic Prenatal,Prenatal Ultrasonic Diagnosis,Prenatal Ultrasonography,Ultrasonic Diagnosis, Prenatal,Ultrasonic Prenatal Diagnosis,Diagnoses, Prenatal Ultrasonic,Diagnoses, Ultrasonic Prenatal,Prenatal Diagnoses, Ultrasonic,Prenatal Ultrasonic Diagnoses,Ultrasonic Diagnoses, Prenatal,Ultrasonic Prenatal Diagnoses
D019001	Nitric Oxide Synthase	An NADPH-dependent enzyme that catalyzes the conversion of L-ARGININE and OXYGEN to produce CITRULLINE and NITRIC OXIDE.	NO Synthase,Nitric-Oxide Synthase,Nitric-Oxide Synthetase,Nitric Oxide Synthetase,Oxide Synthase, Nitric,Synthase, Nitric Oxide