Placental calcium and phosphorus transfer in the guinea pig: lack of effect of modulators of Ca-ATPase and alkaline phosphatase activity.
The effects of modulators of Ca-ATPase and alkaline phosphatase (AP) activity on placental calcium and phosphorus transfer were studied using the in situ perfused guinea pig placenta. The diuretics ethacrynic acid and furosemide had no significant effect on placental calcium and phosphorus transfer when injected into the mother (1.0 or 10.0 mg X kg-1) or added to the solution perfusing the fetal side of the placenta (0.25 or 2.0 mM). These two drugs have previously been shown to inhibit placental Ca-ATPase and enhance AP activity in vitro. D-Penicillamine, which inhibits placental AP but not Ca-ATPase activity in vitro, also had no significant effect on net calcium and phosphorus transfer from mother to fetus either when given to the mother (50 mg X kg-1) or added to the placental perfusion solution (0.25 or 2.0 mM). These results suggest that placental transfer of calcium and phosphorus in the guinea pig may not be directly related to placental Ca-ATPase and AP activities.
D000469:Alkaline Phosphatase / Q000378:metabolism*; D000818:Animals; D000983:Antipyrine / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D004976:Ethacrynic Acid / Q000494:pharmacology; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008431:Maternal-Fetal Exchange; D010396:Penicillamine / Q000494:pharmacology; D010758:Phosphorus / Q000378:metabolism*; D010920:Placenta / Q000378:metabolism; D011247:Pregnancy
D010758:Phosphorus; D000469:Alkaline Phosphatase; D000252:Calcium-Transporting ATPases; D010396:Penicillamine; D004976:Ethacrynic Acid; D002118:Calcium; D000983:Antipyrine