Prenatal Zinc Deficiency and Stress in the Rat

The studies presented below concern the effects of stress upon prenatal zinc deficient adult rats. One group of dams was fed a zinc deficient diet from the morning of day 14 to the morning of day 19 of the pregnancy. A second group was given the same amount of food as was eaten by their zinc deficient counterpart (pair-fed) plus water containing 50 ppm zinc, thus they were not zinc deficient but did experience starvation. A third group was fed the diet ad libitum and given the zinc-supplemented water. Starting at 150 days of age three offspring from each of the above nutritional groups, either all male or female, were placed under stress. The stress consisted of 48 hours of food deprivation followed by 72 hours in an executive animal apparatus. This method was developed by Rice (1963) and modified to its present form by Weiss (1971). Measures of stress include: 1) weight loss during the 48 hours of food deprivation and during the 72 hours in the executive animal apparatus; 2) water consumption, wheel turns and shocks received while in the executive animal apparatus; and 3) gastric pathologies (total length and number were measured from scaled photographs of the fixed stomachs). Zinc deficient males had less lower stomach pathology than normal rats. It was suggested that this group was culled at birth in a way that left the group less prone to lower stomach pathology. Abnormally high mortality rates observed in zinc deficient litters could make this possible. Among executive and yoke stress groups, normally nourished ^s had fewer upper stomach pathology than either pair fed or zinc deficient _Ss. Wheel turning and shock rates of zinc deficient rats were dramatically higher than those of normal rats. This effect was most pronounced in the females and during the first two trial blocks. The upper stomach pathology, wheel turning and shock rate findings are yet further demonstrations of performance and physical impairments resulting from malnutrition, in particular zinc deficiency. Raw data is not appended because of the physical bulk that would be required. Data in any reasonable format will be furnished upon request by the author