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ARS Home » Plains Area » Grand Forks, North Dakota » Grand Forks Human Nutrition Research Center » Dietary Prevention of Obesity-related Disease Research » Research » Publications at this Location » Publication #107707

Title: THE EFFECT OF IDIORRHYTHMIC ZINC DOSE-RATE FEEDING ON THE INDUCTION OF INTESTINAL METALLOTHIONEIN

Author
item MOMCILOVIC, BERISLAV - INST MED RES, CROATIA
item REEVES, PHILLIP

Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: 12/10/1999
Publication Date: 3/15/2000
Citation: Momcilovic, B., Reeves, P.G. 2000. The effect of idiorrhythmic zinc dose-rate feeding on the induction of intestinal metallothionein [abstract]. The Federation of American Societies for Experimental Biology Journal. 14:A512.

Interpretive Summary:

Technical Abstract: We investigated whether feeding intermittent high doses of zinc (Zn) can bypass the regulatory control mechanism in the gastrointestinal tract. This was accomplished by studying the effects of idiorrhythmic dose-rate feeding of Zn on the induction of intestinal metallothionein (iMT) in young growing male rats. The idiorrhythmic approach requires that the average dietary Zn concentration (modulo, M) over the whole experiment (epoch, E) is kept constant across different groups. This is done by adjusting the Zn concentration of the supplemented diet to compensate for the reduction in the number of days on which this diet is fed, the latter being spread evenly over the experiment. Idiorrhythms (I) involve offering the diet with n times the overall Zn concentration (M) only every n**th day with a Zn-deficient diet offered on other days (Momcilovic, J.Nutr. 1995; 125:2687). Three modulos were studied (Low Zn, M3; Adequate Zn, M12; and High Zn, M48), each M having 8 analogous idiorrhythms (I = Mx/1 to 8Mx/8); every I was fed over a 48-d idiorrhythmic E. Over the wide range of the peak doses of dietary Zn (3-384 mg /kg diet), the higher the modulo, the greater the capacity for iMT to be induced (M3 < M12 < M48; P<0.05). Also, the ability of Zn to induce iMT generally increased with the progression of the idiorrhythms from I = Mx/1 to 8Mx/8; P<0.001), although in M3, iMT did not increase until Iò7; for M12 there was no increase until Iò5; for M48 iMT up to I=7. When rats were fed M3, less Zn was required to induce iMT than when they were fed M12 or M48. Thus, within the M and E limits of this study, the better the nutritional Zn status of the animal, the more zinc is required to induce iMT and vice versa.