|STEPHENS, AMANDA - McCormick, Inc|
|SANDERS, TIMOTHY - Former ARS Employee|
Submitted to: Journal of the American Association for Laboratory Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/15/2014
Publication Date: 7/16/2015
Citation: Stephens, A.M., Sanders, T.H. 2015. blood lipid distribution, aortic cholesterol concentrations, and selected inflammatory and bile metabolism markers in syrian hamsters fed a standard breeding diet. Journal of the American Association for Laboratory Animal Science. Vol. 54 (4).
Interpretive Summary: The onset of diseases of the cardiovascular system in humans is related to the types and amounts of fats in the blood as well as buildup of cholesterol in major arteries. Diet is thought to play a part both in the cause and prevention of these diseases. The cardiovascular system of Syrian Golden Hamsters has been found to be a model of that in humans. Feeding studies with high cholesterol diets have been found to induce symptoms of cardiovascular disease. This study investigated the effects of animal age on the onset of the symptoms when fed a standard diet. Several markers such as total cholesterol in the aorta, total blood plasma cholesterol, and other markers related to the atherosclerosis development were monitored from the age of 7 weeks to 31 weeks of age. The results showed that disease risk factors did not increase with age. This information is useful in planning dietary studies using this animal model as it allows for changes to be attributed to the diet rather than to normal aging factors.
Technical Abstract: Hamsters are often used to determine the effects of various dietary ingredients on the development of cardiovascular disease (CVD). The study was conducted to obtain baseline data on CVD risk factors and mRNA expression of selected genes in hamsters fed a standard maintenance diet (STD) for 24 wk, beginning when animals were 7 wk old. Plasma triacylglycerol and aortic cholesteryl ester concentrations did not significantly change during the study. Total plasma cholesterol (75.9-127.9 mg/dL), LDL- (3.2-12.2 mg/dL), and HDL- (53.8-98.9 mg/dL) cholesterols increased over the 24wk study. Aortic total cholesterol increased from 9.72 to 12.20 µg/mg protein, whereas aortic cholesteryl ester, a measure of atherosclerosis development, was less than 0.18 µg/mg protein throughout the study. The expression of hepatic endothelin 1, peroxisome proliferator-activated receptor a, and hepatic cholesterol 7-a-hydroxylase mRNA did not change throughout the study, indicating that fatty acid ß-oxidation and cholesterol metabolism remained consistent. The mRNA expression of ATP-binding cassette, subfamily B member 11 increased between wk 0 and 8 but then remained unchanged, suggesting increased requirements for cholesterol in early growth. These results indicate that the consumption of a STD does not increase atherosclerotic disease risk factors in golden Syrian hamsters through 31 wk of age.