Tongue Microvasculature and Mechanical Characteristics of the Femur Bone in Zinc-deficient Rats

Abstract

Male Wistar strain rats were fed a zinc (Zn) deficient diet for 4 weeks and the tongue microvasculature and mechanical characteristics of the femur bone studied in order to determine the biological effects of Zn. The following results were obtained. 1. Rats fed the Zn-deficient diet consumed less feed than the control group, and body weight gain was suppressed. 2. Macroscopic findings that are characteristic of Zn deficiency, such as skin symptoms and piloerection, were observed in the Zn-deficiency group from about 3 weeks after starting the experiment. 3. Serum Zn concentrations and serum ALP activity were significantly lower in the Zn-deficiency group compared to the control group. 4. Tongue Zn concentrations were significantly lower in the Zn-deficiency group than in the control group. 5. Femur length and bone density, as well as the maximum asymmetry and maximum bending stress were significantly less in the Zn-deficient group compared to the control group. 6. Leakage from the tongue microvasculature was observed in the Zn-deficient group from an electron microscopic image of the tongue microvasculature. The results of the present study suggest that taste abnormalities due to Zn deficiency are related to impairment of the tongue microvasculature, which is the nutrient supply route for the taste buds, and that impaired growth and decreased bone strength in the femur are caused by Zn deficiency.