Biomaterial Database

Uptake of amino acids and ammonia at mid-gestation by the fetal lamb. 1989

A W Bell, and J M Kennaugh, and F C Battaglia, and G Meschia

Department of Pediatrics, University of Colorado School of Medicine, Denver 80262.

Fetal uptakes of amino acids and ammonia via the umbilical circulation were measured in single pregnant ewes at mid-gestation (range 66-81 days). There were significant net fluxes from placenta to fetus of ammonia and twelve amino acids (in decreasing order: glutamine, glycine, alanine, proline, lysine, arginine, threonine, valine, leucine, tyrosine, asparagine, isoleucine) and net fluxes from fetus to placenta of glutamate and serine. The estimated serine flux was 139 mumol day-1 (g fetal dry wt)-1. Comparison with late gestation data indicated a similar pattern of amino acid exchange. However, the relatively large placental uptake of fetal serine was a distinctive feature of mid-gestation. The net fetal uptake of amino acid nitrogen was 2.83 +/- 0.66 micrograms N (mumol O2 uptake)-1, or 18 mg N day-1 (g dry wt)-1. This uptake was similar in magnitude to the combined fetal requirements for nitrogen accretion and urea synthesis and represented approximately 32 and 43% of fetal carbon and energy requirements, respectively.

UI	MeSH Term	Description	Entries
D009584	Nitrogen	An element with the atomic symbol N, atomic number 7, and atomic weight [14.00643; 14.00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth's atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells.
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
D002244	Carbon	A nonmetallic element with atomic symbol C, atomic number 6, and atomic weight [12.0096; 12.0116]. It may occur as several different allotropes including DIAMOND; CHARCOAL; and GRAPHITE; and as SOOT from incompletely burned fuel.	Carbon-12,Vitreous Carbon,Carbon 12,Carbon, Vitreous
D004734	Energy Metabolism	The chemical reactions involved in the production and utilization of various forms of energy in cells.	Bioenergetics,Energy Expenditure,Bioenergetic,Energy Expenditures,Energy Metabolisms,Expenditure, Energy,Expenditures, Energy,Metabolism, Energy,Metabolisms, Energy
D005260	Female		Females
D005333	Fetus	The unborn young of a viviparous mammal, in the postembryonic period, after the major structures have been outlined. In humans, the unborn young from the end of the eighth week after CONCEPTION until BIRTH, as distinguished from the earlier EMBRYO, MAMMALIAN.	Fetal Structures,Fetal Tissue,Fetuses,Mummified Fetus,Retained Fetus,Fetal Structure,Fetal Tissues,Fetus, Mummified,Fetus, Retained,Structure, Fetal,Structures, Fetal,Tissue, Fetal,Tissues, Fetal
D005865	Gestational Age	The age of the conceptus, beginning from the time of FERTILIZATION. In clinical obstetrics, the gestational age is often estimated from the onset of the last MENSTRUATION which is about 2 weeks before OVULATION and fertilization. It is also estimated to begin from fertilization, estrus, coitus, or artificial insemination.	Embryologic Age,Fetal Maturity, Chronologic,Chronologic Fetal Maturity,Fetal Age,Maturity, Chronologic Fetal,Age, Embryologic,Age, Fetal,Age, Gestational,Ages, Embryologic,Ages, Fetal,Ages, Gestational,Embryologic Ages,Fetal Ages,Gestational Ages
D000596	Amino Acids	Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.	Amino Acid,Acid, Amino,Acids, Amino
D000641	Ammonia	A colorless alkaline gas. It is formed in the body during decomposition of organic materials during a large number of metabolically important reactions. Note that the aqueous form of ammonia is referred to as AMMONIUM HYDROXIDE.