Hamsters predisposed to sucrose-induced cholesterol gallstones (LPN strain) are more resistant to excess dietary cholesterol than hamsters that are not sensitive to cholelithiasis induction.
We compared the effects of cholesterol feeding in male hamsters from two strains with different propensities to sucrose-induced cholelithiasis; Laboratoire de Physiologie de la Nutrition (LPN) hamsters are predisposed to developing biliary cholesterol gallstones, whereas Janvier (JAN) hamsters are not. When fed a basal control diet, LPN hamsters had a lower cholesterolemia (-21%, P = 0.01) than JAN hamsters, and a higher activity of 3-hydroxy-3-methyl glutaryl coenzyme A reductase in liver (+148%, P = 0.018) and intestine (+281%, P < 0.0001). After feeding the same diet enriched with 0.3% cholesterol for 5 wk, cholesterolemia increased more dramatically in JAN hamsters (+235%, P < 0.001) than in LPN hamsters (+108%, P < 0.001), as did the liver concentration of cholesterol, which reached 152.30 +/- 13.00 and 44.41 +/- 9.06 micromol/g, respectively. Only JAN hamsters displayed hepatomegaly, with an increased cholesterol saturation index of the gallbladder bile (+100%, P < 0.01), due to the cholesterol challenge. In liver, cholesterol feeding reduced cholesterol 7alpha-hydroxylase activity and mRNA level, and stimulated sterol 27-hydroxylase and oxysterol 7alpha-hydroxylase activities. Hepatic levels of LDL receptor decreased by approximately 60% in both strains, whereas HDL receptor scavenger class B type 1 (SR-BI) levels were unaffected by dietary cholesterol. The greater resistance of LPN hamsters to the hypercholesterolemic diet can be explained by a lower capacity to store cholesterol in the liver and greater efficiency in reducing the activity of 3-hydroxy-3-methyl glutaryl coenzyme A reductase in response to cholesterol feeding [from 11263 to 261 pmol/(min x organ) in LPN hamsters and from 4530 to 694 pmol/(min x organ) in JAN hamsters]. These results highlight the usefulness of this two-strain model, which offers some analogy with the inverse association between the predisposition to cholelithiasis and the risk of atherosclerosis in humans.
Souidi
M
M
Laboratoire de Physiologie de la Nutrition-INRA, Université Paris XI, F-91405 Orsay Cedex, France.
Combettes-Souverain
M
M
Milliat
F
F
Eckhardt
E R
ER
Audas
O
O
Dubrac
S
S
Parquet
M
M
Férézou
J
J
Lutton
C
C
D000818:Animals; D001647:Bile Acids and Salts / Q000096:biosynthesis; D001835:Body Weight; D002769:Cholelithiasis / Q000139:chemically induced*; D053493:Cholestanetriol 26-Monooxygenase; D002790:Cholesterol 7-alpha-Hydroxylase / Q000378:metabolism; D002791:Cholesterol, Dietary / Q000494:pharmacology*; D006224:Cricetinae; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D004351:Drug Resistance; D006903:Hydroxymethylglutaryl CoA Reductases / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism; D008055:Lipids / Q000032:analysis / Q000097:blood; D008099:Liver / Q000378:metabolism; D008297:Male; D008647:Mesocricetus; D009929:Organ Size; D012333:RNA, Messenger / Q000032:analysis; D011973:Receptors, LDL / Q000378:metabolism; D013250:Steroid Hydroxylases / Q000378:metabolism; D013395:Sucrose
D001647:Bile Acids and Salts; D002791:Cholesterol, Dietary; D008055:Lipids; D012333:RNA, Messenger; D011973:Receptors, LDL; D013395:Sucrose; D003577:Cytochrome P-450 Enzyme System; D006903:Hydroxymethylglutaryl CoA Reductases; D013250:Steroid Hydroxylases; D002790:Cholesterol 7-alpha-Hydroxylase; D053493:Cholestanetriol 26-Monooxygenase