Dietary regulation of maternal and fetal cholesterol metabolism in the guinea pig.
Studies to determine the effects of pre-natal interventions on maternal and fetal cholesterol homeostasis were carried out in the guinea pig. Guinea pig dams were fed either non-purified guinea pig diet or diet supplemented with either 1.1% of the bile acid binding resin cholestyramine or 0.25% cholesterol. Whole body rates of endogenous cholesterol synthesis were determined by quantitation of [3H]water incorporation into digitonin precipitable sterols in non-pregnant animals and at 40 and 60 days of gestation in the dam and fetus. Maternal hepatic cholesterol synthesis was reduced 87% by dietary cholesterol and was increased 3.5-fold with cholestyramine feeding. Fetal hepatic and peripheral tissue cholesterol synthesis rates peaked at 40 days gestation when peripheral tissue cholesterol synthesis was 5.7-fold higher and hepatic synthesis 6.2-fold greater than the near adult levels observed at 60 days. Cholesterol synthesis in the fetus was relatively insensitive to dietary manipulations; however, maternal cholestyramine treatment did result in a 1.4-fold increase in fetal carcass cholesterol synthesis at 60 days gestation. These data demonstrate that maternal cholesterogenic systems maintain responsiveness to dietary regulation during pregnancy; whereas fetal cholesterol homeostasis is relatively insensitive to dietary cholesterol throughout gestation yet may respond to induction by maternal cholestyramine treatment during the late gestation period.
Yount
N Y
NY
Department of Nutrition & Food Science, University of Arizona, Tucson 85721.
McNamara
D J
DJ
D000818:Animals; D001835:Body Weight; D002784:Cholesterol / Q000096:biosynthesis / Q000097:blood / Q000378:metabolism*; D002791:Cholesterol, Dietary / Q000008:administration & dosage; D002792:Cholestyramine Resin / Q000008:administration & dosage; D004032:Diet; D005314:Embryonic and Fetal Development; D005260:Female; D005333:Fetus / Q000378:metabolism*; D005865:Gestational Age; D006168:Guinea Pigs; D006903:Hydroxymethylglutaryl CoA Reductases / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000378:metabolism*
D002791:Cholesterol, Dietary; D002792:Cholestyramine Resin; D002784:Cholesterol; D006903:Hydroxymethylglutaryl CoA Reductases