Effects of maternal undernutrition and uterine artery ligation on placental lipase activities in the rat.

Lipase activities measured at pH 4 and 8 were determined in the placentas of rats subjected to undernutrition or uterine artery ligation. The fetal lipid content following maternal undernutrition was also determined. The placental lipase activity (per gram placenta) measured at pH 8 (placental lipoprotein lipase) remained unchanged, whilst the activity of the intracellular lipase (per gram placenta) measured at pH 4 was significantly less than in the control group (21% lower in maternal undernutrition and 16% lower after uterine artery ligation). Although placentas and fetuses were significantly lighter in both situations as compared to controls (well-nourished or sham operated, respectively), fetal lipid content in maternal undernutrition was only reduced to a degree concomitant with the decrease in fetal weight. We therefore conclude that the intracellular lipase may not have an important role in the provision of free fatty acids in undernutrition.