Effect of cholesterol feeding on circadian rhythm of hepatic and intestinal cholesterol biosynthesis in hamsters.
Forty-eight adult hamsters were divided equally into two groups fed a control diet and a 2% cholesterol diet, respectively, under a rigid lighting (6 PM-6 AM) and feeding (6 PM-8 AM) schedule for three weeks. The cholesterol synthetic activity of the liver, stomach, small intestine, cecum, colon and kidney was measured by in vivo conversion of acetate-1-14C to cholesterol in four animals each time at 4 hour intervals. A remarkable circadian rhythm with the peak at midnight and the nadir at noon was found in the liver of the control hamsters, but was completely abolished in the cholesterol-fed animals since the activity was nearly totally suppressed at all times. The small intestine exhibited a similar rhythm with the peak at midnight but maintained a high baseline activity from 8 AM to 6 PM. Cholesterol feeding did not alter the baseline activity but reduced 17% of the peak activity. Other organs failed to show such a circadian rhythm.
D000818:Animals; D001835:Body Weight; D002784:Cholesterol / Q000096:biosynthesis*; D002791:Cholesterol, Dietary / Q000008:administration & dosage; D002940:Circadian Rhythm / Q000187:drug effects*; D006224:Cricetinae / Q000502:physiology*; D004435:Eating; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000033:anatomy & histology; D007668:Kidney / Q000033:anatomy & histology; D008099:Liver / Q000033:anatomy & histology / Q000378:metabolism*; D008297:Male; D009929:Organ Size
D002791:Cholesterol, Dietary; D002784:Cholesterol