Extracellular binding of calcium in the guinea-pig placenta.
Extraction of 45Ca from the perfused umbilical vascular bed of the guinea-pig placenta was measured using 3H-sucrose or 24Na as reference substances at a constant inflow concentration of the tracers. La3+ (5mM) depressed extraction of 45Ca below zero for several minutes. This suggests that there is a significant amount of Ca bound extracellularly on the umbilical side of the placental barrier.
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D005110:Extracellular Space / Q000378:metabolism*; D005260:Female; D006168:Guinea Pigs; D008433:Mathematics; D010920:Placenta / Q000166:cytology* / Q000378:metabolism; D011247:Pregnancy; D012964:Sodium / Q000378:metabolism; D013395:Sucrose / Q000378:metabolism
D013395:Sucrose; D012964:Sodium; D002118:Calcium