Transfer of fatty acid across the cat placenta.
The transfer of fatty acids across the placenta was investigated in six anaesthetised pregnant cats at 60 days gestation (term 64-66 days). 1-14C palmitic acid bound to albumin was infused for 20 min and blood samples taken from a maternal artery and the umbilical vessels of the fetuses as they were delivered serially by Caesarean section either during and immediately after the infusion. Fetal blood and organs were analysed with respect to fatty acid content and presence of labelled fatty acid. The maternal and fetal plasma free fatty acid concentrations were 0.32 +/- 0.02 and 0.18 +/- 0.02 mmol/L (mean +/- SE) respectively. There was no significant umbilical v-a difference and no correlation between maternal and fetal concentrations. The specific activity of labelled palmitic acid in the fetal circulation was less than 1% of that in the maternal circulation but there was a very small but significant umbilical v-a difference during the infusion. The percentage composition of arachidonic acid in maternal plasma free fatty acid was 4.0%; in fetal plasma free fatty acid 5.8%; in fetal plasma triacylglycerol 1.9%; in fetal adipose tissue triacylglycerol 0.6%, and in fetal brain total fatty acids 12.9%. It is concluded that in the cat fatty acids do not pass freely from the maternal free fatty acid to the fetal free fatty acid compartment. It is suggested that as arachidonic acid forms a higher fraction of fetal than of maternal plasma free fatty acid and as the cat tissues are unable to convert linoleic to arachidonic acid, the possibility that fetal arachidonic acid is derived from maternal plasma phospholipids must be considered.
D002001:Adipose Tissue, Brown / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000378:metabolism; D002250:Carbon Radioisotopes; D002415:Cats / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism*; D005230:Fatty Acids, Nonesterified / Q000097:blood / Q000378:metabolism; D005260:Female; D005312:Fetal Blood; D008099:Liver / Q000378:metabolism; D008431:Maternal-Fetal Exchange; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000494:pharmacology; D010743:Phospholipids / Q000097:blood; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D014280:Triglycerides / Q000097:blood / Q000378:metabolism
D002250:Carbon Radioisotopes; D005227:Fatty Acids; D005230:Fatty Acids, Nonesterified; D010169:Palmitic Acids; D010743:Phospholipids; D014280:Triglycerides; D019308:Palmitic Acid