Effect of enhancement of cholesterol catabolism in guinea pigs after weaning on subsequent response to dietary cholesterol

Abstract

Cholesterol catabolism was stimulated (by cholestyramine) in post-weaned guinea pigs for a 4-wk period. The animals were then switched to regular Chow diet for another 4 wk. When subsequently challenged with 0.25% cholesterol-containing Chow, plasma cholesterol level was significantly (p less than 0.05) lower in cholestyramine pretreated guinea pigs when compared to control guinea pigs and this "hyporesponder" pattern was maintained throughout the study period. Cholestyramine pretreated animals continued to excrete significantly (p less than 0.05) higher bile acids even at 4 wk after switching to regular Chow diet. This study demonstrates that stimulation of cholesterol catabolism even at postweaning stages can still be as effective in improving subsequent cholesterol handling capacity as noted previously after manipulation at the neonatal stage.

Treatment of young rats with cholestyramine or a hypercholesterolemic diet does not influence the response of serum cholesterol to dietary cholesterol in later life

“…The liver responds by converting more cholesterol into bile acids. The increased production of bile acids induced by cholestyramine in the diet of the guinea pigs persisted after the withdrawal of the drug [7,8]. This persistent effect may be related to the improved handling of dietary cholesterol at the later stage.…”

“…Other studies with rats have shown a negative [9, lo], positive [11,19] or no association at all [12- [7] guinea pigs previous cholestyramine feeding reduced the cholesterolemic response to cholesterol loading during later life. Cholestyramine, a basic anion exchange resin, binds bile acids in the gut and carries them into the feces [7,8] thereby causing a drain on the bile acid pool. The liver responds by converting more cholesterol into bile acids.…”

“…Animal studies are therefore indicated to provide more information as to possible imprinting effects on cholesterol metabolism. Feeding of the serum cholesterol lowering bile acid binding resin, cholestyramine, for 4-6 weeks significantly lowered the response of serum cholesterol to dietary cholesterol measured 4 to 6 weeks later in neonatal [7] and post-weaned [8] guinea pigs. No such data are available for rats.…”

Dietary Cholesterol and Fats at a Young Age: Do They Influence Cholesterol Metabolism in Adult Life?

“…In gerbils that were pre treated only for 1 month, no effects were found at 6 months. Based on the literature [Li et al, 1979, 1980: Kris-Etherton et al, 1979Hassan et al, 1982], we speculated that bile acid metabolism might be of impor tance to explain possible delayed effects of the pretreatment regimen. Though in experi ment II bile acid excretion was enhanced on all diets in comparison with diet B, and therefore probably bile acid synthesis also, yet in experiments IV and V we found no differences in bile acid excretion.…”

“…1982;Green et al, 1981;Beynen et al, 1985]. However, low response has been found in the guinea pig after stimulating cholesterol catabolism with cholestyramine in the neonatal period [Li et al, 1979[Li et al, , 1980Hassan et al. 1982].…”