Influence of Strain Differences on Serum Cholesterol Levels in Rats

Abstract

The purpose of this study was to clarify the relationship between rat strain and the serum cholesterol level.Wistar, Donryu and Sprague-Dawley strain rats of both sexes were divided into 2 groups and fed on the following two kinds of diet for 10 days; a standard diet not containing cholesterol and a cholesterol diet containing 1% cholesterol and 0.25% bile salts. After 10 days, the animals were fasted overnight and the serum total cholesterol level was measured.Wistar strain was very similar to the Donryu strain in respect of the serum cholesterol level. In both strains, serum cholesterol levels in rats placed on the standard diet were about 80mg/dl, regardless of sex. Dietary cholesterol caused a rather significant increase in serum cholesterol levels reaching 100-110mg/dl, regardless of strain or sex.Sprague-Dawley strain rats fed on the standard diet showed a higher serum cholesterol level (about 100mg/dl) than the Wistar or Donryu strains. When the Sprague-Dawley rats were placed on the cholesterol diet, a marked elevation in the serum cholesterol value was observed in the males (156mg/dl) and furthermore in the females (256mg/dl).Liver total cholesterol level of the Sprague-Dawley rats maintained on the cholesterol diet was also the highest among the three strains.