Analysis of cyclic feed intake in rats fed on a zinc-deficient diet and the level of dihydropyrimidinase (EC3.5.2.2)

Abstract

The body weight and feed intake of rats fed on a Zn-deficient diet for 28 d were reduced compared with those of control rats. The feed intakes of the Zn-deficient and control groups during the period were 10.2 (SE 0.3) and 15-7 (SE 0.2) g/d respectively. Cyclic variations in feed intake and body-weight changes were found in analysis not only of all the data for five rats but also that in each individual rat. Cosinor analysis revealed that the cyclical period of both the feed intake and body-weight change in the Zn-deficient rats was 3.5 (SE 0.1) d. The mesor and amplitude value of the feed intake in the Zn-deficient rats was 10.1 (SE 0.4) g/d and 3 5 (SE 0.5) g/d respectively, and that of body-weight change was 1.4 (SE 0.1) g/d and 7.9 (SE 1.3) g/d respectively. Among pyrimidine-catabolizing enzymes, dihydropyrimidinase (EC 3.5.2.2) activity showed significant retardation in the Zn-deficient rat liver with decrease of the enzyme protein.The ratio of apo-form to holo-form dihydropyrimidinase in the liver was not alfected by the Zndeficient diet.Zinc deficiency : Cosinor analysis : Dihydropyrimidinase

Modulation of Maltose Preference by Selection from Dextrin, Maltose and Glucose Diets in Zinc-Deficient Rats

“…The body-weight changes in The period of the body-weight change cycle was the same as that of the food intake cycle. The body-weight changes follow the food intake of rats fed a Zn-deficient diet, as shown in the previous papers (4,33,34). Neither the total food intake nor body-weight change, in the Znadequate rats was correlated to a Cosinor curve.…”

Change to a Preference for Maltose from Sucrose over Days in Zn-Deficient Rats Selecting from Maltose and Sucrose Diets

“…The daily food intake of rats fed a Zn-deficient diet shows a characteristic variation and fits well to a cosine curve (12)(13)(14). But force-feeding Zn-deficient rats with 140% of their voluntary intake rapidly induces severe signs of illness ( 5 ).…”

“…Daily food intake and body weight change data from Zn-deficient rats were analyzed by the Cosinor method (12)(13)(14). Food intake ( F ) and body weight change ( ⌬ B ) on day t were determined using the following equation:…”

“…Rats fed a zinc (Zn)-deficient diet show reduction of food consumption and growth retardation (1)(2)(3). The decreased food intake of rats fed a Zn-deficient diet shows a characteristic cyclic pattern with a 3.5-4.0 d period (4)(5)(6)(7)(8)(9)(10)(11)(12). The decreased food intake of rats fed a Zn-deficient diet follows growth retardation ( 13 , 14 ).…”

Cosinor Analysis of Feed Intake Cycle of Rats Fed a Zinc-Deficient Diet and the Effect of Zinc Supplementation.

“…In our preliminary study (14), the calculated cyclic period was 3 .5 d for both feed intake and body-weight change in Zn-deficient rats. In this study, we analyzed the correlations among the parameters of feed intake and body-weight change cycles separately, as well as those between the two cycles.…”