The clearance and placental transfer of free fatty acids and triglycerides in the pregnant guinea-pig.
Bolus injections of [14C]palmitic acid and endogenously prepared very low density lipoprotein (VLDL) were given to 12 guinea-pigs in late gestation in whom the fetal side of the placenta was perfused in situ. Disappearance of [14C] palmitate in the mother was rapid, with a half life of 2.4 min. The [14C] palmitic acid which crossed the placenta into the perfusate disappeared in parallel with the maternal label but with a delay time of 1.6 min. Following injection of [14C] labelled very low density lipoprotein maternal plasma [14C] triglyceride declined rapidly (half life of 0.7 to 9.8 min) and gave rise to [14C] free fatty acids in the plasma. These fatty acids disappeared at a slower rate (half life of 13.5 min) than found following [14C]palmitate bolus. No [14C] triglyceride appeared to cross the placenta, but triglyceride derived free fatty acids did with a delay time of 9.4 min. In experiments performed after 55 days gestation quantities of [14C] free fatty acids were higher in the perfusate than in maternal plasma implying hydrolysis of triglyceride within the placenta. It is concluded that maternal triglyceride may make a considerable contribution to fetal lipids which increases with gestational age.
D000818:Animals; D002250:Carbon Radioisotopes; D005230:Fatty Acids, Nonesterified / Q000378:metabolism*; D005260:Female; D006168:Guinea Pigs; D006207:Half-Life; D008079:Lipoproteins, VLDL / Q000378:metabolism; D008431:Maternal-Fetal Exchange; D008657:Metabolic Clearance Rate; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000378:metabolism; D010920:Placenta / Q000378:metabolism; D011247:Pregnancy; D014280:Triglycerides / Q000378:metabolism*
D002250:Carbon Radioisotopes; D005230:Fatty Acids, Nonesterified; D008079:Lipoproteins, VLDL; D010169:Palmitic Acids; D014280:Triglycerides; D019308:Palmitic Acid