Altered response of stressed rats to hypercholesterolemic diets

✍ Scribed by Fawzi Dabora; Michael M. Clay

• Publisher: John Wiley and Sons
• Year: 1964
• Tongue: English
• Weight: 225 KB
• Volume: 53
• Category: Article
• ISSN: 0022-3549
• DOI: 10.1002/jps.2600531040

✦ Synopsis

Rats were stressed for 2 weeks by restriction of movement, then fed a diet containing cholesterol, cholic acid, and calciferol for 2 weeks. The prestressed rats developed higher levels of plasma cholesterol and atherosclerosis than did unstressed controls. Plasma cholesterol increased in prestressed rats when the diet was supplemented with 250, 500, and 2000 U.S.P. units of calciferol. The degree of atherosclerosis was not directly related to the degree of hypercholesterolemia in all cases.

NVIRONMENTAL "STRESS" is one of the factors E being studied in the elucidation of the mechanisms of atherosclerosis. Increases in serum cholesterol levels have been reported in students in response to the "stress" posed by examinations (14). Page et al. (€9, however, failed to find a causal relationship between changes in plasma levels of cholesterol, lipoprotein, or triglycerides and short-term "stresses" (tournament bridge playing and performance of surgery).

The contradictory results obtained in human studies may be due to nonuniform definitions of the state referred to as "stress" as well as to the varying periods of exposure to an unpleasant environment. Also, human studies are limited by lack of knowledge of prestudy experience and inability to study blood vessels for evidence of atherosclerosis.

After 14 days of partial restriction of movement of rats, Gabel and Clay (6) reported that systolic blood pressures were elevated. Further studies in this laboratory have demonstrated that peripheral plasma corticmterone levels were sharply increased by restriction of movement in rats. Page and Brown (7) reported that rats fed a diet containing