Transplacental differences in Ca, Na, K, and electropotential in the guinea pig

Technical Report · Fri Jul 01 00:00:00 EDT 1983

OSTI ID:5849899

Kelman, B J; Twardock, A R

The fetal side of hemochorial placentas from guinea pigs between 58 and 62 days gestation were perfused in situ. Concurrent measurements were made of the clearances of radiocalcium and tritiated water from maternal to fetal circulation of the placenta, transplacental potential difference (TPD), maternal plasma and perfusate Ca, Na, and K concentrations, maternal blood pressure, gross permeability of albumin in the placenta, and net water movements. Movement of Ca from dam to fetus appeared to occur against an electrochemical gradient and was not associated with the movements of Na and K across the placenta. A negative correlation between perfusate Na and K concentrations, not dependent on maternal plasma Na and K concentrations and abolished by high concentrations of Ca in the fetal circulation of the placenta, strongly supports the concept of a Na-K exchange mechanism in the placenta directed so that K is moved against a concentration gradient towards the dam. There was no evidence that the TPD existed at the site of maternal-fetal exchange for Ca, Na, or K.

• Research Organization: Pacific Northwest Lab., Richland, WA (USA)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 5849899
• Report Number(s): PNL-SA-9839; ON: DE83015090; TRN: 83-019358
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CALCIUM
MEMBRANE TRANSPORT
GUINEA PIGS
PLACENTA
PERMEABILITY
POTASSIUM
SODIUM
CALCIUM 45
CLEARANCE
EXPERIMENTAL DATA
PERFUSED TISSUES
TRACER TECHNIQUES
TRITIUM
ALKALI METALS
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METALS
ANIMAL TISSUES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CALCIUM ISOTOPES
DATA
DAYS LIVING RADIOISOTOPES
ELEMENTS
EVEN-ODD NUCLEI
FETAL MEMBRANES
HYDROGEN ISOTOPES
INFORMATION
INTERMEDIATE MASS NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
MAMMALS
MEMBRANES
METALS
NUCLEI
NUMERICAL DATA
ODD-EVEN NUCLEI
RADIOISOTOPES
RODENTS
TISSUES
VERTEBRATES
YEARS LIVING RADIOISOTOPES
551001* - Physiological Systems- Tracer Techniques