EFFECTS OF DIETARY RESTRICTION ON AGE-ASSOCIATED PATHOLOGIC CHANGES IN F-344 RATS

抄録

The present report concerns the inhibitory effect of dietary restriction on the age-associated pathologic changes destined to occur in Fisher (F-344) rats.
A total of 360 rats of both sexes were divided into 3 groups consisting 60 males and 60 females each. Rats of the first group were fed a standard commercial diet CRF-1 ad libitum. The second, daily restricted group was given about 8gm and 12gm of diet daily (approximately 67% of ad libitum intake) in females and males, respectively. The third, intermittent feeding group was fed twice a week for a total amount of 67% of ad libitum intake (28gm for females and 41gm for males each time). Ten animals of each group were necropsied after one year and the remaining 50 animals of each group were maintained for two years.
Twelve females and 15 males in the ad libitum feeding group, 7 females and 10 males in the daily restricted group, and 10 females and 6 males in the intermittent feeding group died during the experimental period. Body weight was decreased approximately 52% to 63% in both food restricted groups relative to the ad libitum feeding group. The occurrence of tumors, i.e., pituitary tumors, mononuclear cell leukemia, testicular interstitial tumors, and breast tumors, was significantly suppressed in these food restricted groups relative to the ad libitum feeding group. Non-neoplastic lesions, such as chronic nephropathy and myocardiopathy were markedly reduced in food restricted groups. As the most noticeable laboratory finding, a marked reduction of plasma lipid peroxide level was noted in the food restricted groups.