Transplacental 45Ca and 32P flux in the guinea pig: effect of maternal hypercalcaemia and hypocalcaemia
| Autor: | L. O. Derewlany, I. C. Radde |
|---|---|
| Rok vydání: | 1985 |
| Předmět: |
medicine.medical_specialty
Time Factors Hypercalcaemia Physiology Placenta Guinea Pigs Biology Guinea pig Pregnancy Physiology (medical) Internal medicine medicine Animals Hypocalcaemia Egtazic Acid Maternal-Fetal Exchange Pharmacology Hypocalcemia Calcium Radioisotopes Transplacental Phosphorus General Medicine medicine.disease Calcium Gluconate medicine.anatomical_structure Endocrinology Hypercalcemia Gestation Calcium Female Phosphorus Radioisotopes Flux (metabolism) |
| Zdroj: | Canadian Journal of Physiology and Pharmacology. 63:1577-1580 |
| ISSN: | 1205-7541 0008-4212 |
| DOI: | 10.1139/y85-259 |
| Popis: | Transplacental 45Ca and 32P flux was measured across the in situ perfused guinea-pig placenta under conditions of acute maternal hypocalcaemia and hypercalcaemia. Maternal hypercalcaemia induced acutely by calcium gluconate infusion caused an increase in maternal-to-fetal 45Ca flux which was proportional to the increase in maternal plasma ionized calcium concentration. Acute maternal hypocalcaemia was induced by EGTA infusion and resulted in a decrease in maternal plasma ionized calcium concentration proportional to a corresponding decrease in transplacental 45Ca transfer. A bolus of calcium gluconate caused a transient decrease in 32P flux, whereas EGTA administration was without significant effect on transplacental 32P transfer. Calcium transport across the placenta is not saturated under conditions of maternal normocalcaemia and may be altered according to acute changes in maternal plasma calcium concentration. Thus, control of maternal-to-fetal calcium transfer does not appear to be at the placental level. This suggests that fetal calcium homeostasis may be regulated by the fetus itself. |
| Databáze: | OpenAIRE |
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