Clearance of. cap alpha. -aminoisobutyric acid during in-situ perfusion of the guinea pig placenta

Conference · Sun May 01 04:00:00 EDT 1983

OSTI ID:5921604

Kelman, B J; Sikov, M R

Extensive investigation of the transport of ..cap alpha..-aminoisobutyric acid (AIB; a nonmetabolized amino acid) has shown that AIB is actively transported from mother to fetus across the hemochorial placenta of the guinea pig. As a step towards clarifying the relative rolls of active and passive movements of amino acids across the placenta, it would be useful to obtain concurrent measurements of transplacental movements of a substance which crosses the placenta rapidly by simple diffusion (water) and of a substance which is actively transported across the placenta (AIB). In our study, placentas from guinea pigs between 59 and 61 days of gestation were perfused in situ through cannulated umbilical vessels with the maternal circulation left intact. Tritiated water and /sup 14/C-AIB were injected into a maternal jugular vein and maternal blood samples were obtained at 1 to 10 minute intervals; perfusate samples were collected sequentially after one pass through the placenta. Clearance of /sup 14/C-AIB from mother to fetus (AIB/sub MF/) and AIB concentrations in placental tissue, maternal plasma, and perfusate were consistent in magnitude with data obtained by other invetigators who have clearly shown an active transport of AIB in the placenta. On the other hand, in this study AIB/sub MF/ ranged from approximately 50% to 96% of the clearance of /sup 3/H-labeled water from mother to fetus (T/sub MF/) and that changes in AIB/sub MF/ correlated closely with changes in T/sub MF/ in all perfusions. Thus, it appears that AIB/sub MF/ closely paralleled T/sub MF/ and these data suggest that a relatively large component of AIB/sub MF/ is of passive origin in the in situ placenta.

• Research Organization: Pacific Northwest Lab., Richland, WA (USA)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 5921604
• Report Number(s): PNL-SA-11418; CONF-8210163-1; ON: DE83014533
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
BUTYRIC ACID
CARBON 14
CARBON ISOTOPES
CARBOXYLIC ACIDS
CLEARANCE
COMPARATIVE EVALUATIONS
CORRELATIONS
DATA
DIFFUSION
EVEN-EVEN NUCLEI
EXPERIMENTAL DATA
FETAL MEMBRANES
GUINEA PIGS
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
INFORMATION
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
MAMMALS
MEMBRANE TRANSPORT
MEMBRANES
MONOCARBOXYLIC ACIDS
NUCLEI
NUMERICAL DATA
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
OXYGEN COMPOUNDS
PERFUSED ORGANS
PLACENTA
RADIOISOTOPES
RODENTS
TRACER TECHNIQUES
TRITIUM
VERTEBRATES
WATER
YEARS LIVING RADIOISOTOPES