The effects of feeding a zinc‐deficient diet on taste acuity and tongue epithelium in rats

Abstract

Taste preferences, fluid intake and histology of tongue epithelium were studied in rats fed a zinc-deficient diet and in pair-fed controls. The results of two-bottle preference tests demonstrated that zinc-deficient rats exhibited significantly increased preferences for 1.5 X 10 • M HCL and 1.28 X 10"" M quinine sulfate as well as a significant increase in relative fluid volume intake. Histologic examination of the tongue epithelium of the zincdeficient rats showed a hypercellular prickle cell layer and a marked parakeiatosis. The fungiforni papillae of the zinc-deficient rats exhibited acantliosis and mild parakeratosis. However, the pore region of the taste buds did not seem to be covered by the paiakeratotic epithelium. The results suggest that the impaired taste observed in zinc-deficient rats may not be related to blockage of tastants from the pore region.

Tracing of Zinc Nanocrystals in the Anterior Pituitary of Zinc-Deficient Wistar Rats

“…Reduced activity of salivary carbonic anhydrase was observed by Goto et al [23] after long-term zinc deficiency in rats which causes abnormalities in taste buds ultimately leading to decreased taste sensitivity. It has been observed that zinc deficiency in animals can cause smell disorder and olfactory epithelium disorders [21,22,24]. In the present study, 2 ZD and 4 ZD groups exhibited a significant decrease in diet consumption as compared to their respective control groups.…”

“…Significantly reduced diet consumption in zinc-deficient rats in the index study may be suggested due to taste impairment, smell disorder, salivary and olfactory secretion disorders. Several authors [21,22] reported similar results after zinc deficiency in rats. Reduced activity of salivary carbonic anhydrase was observed by Goto et al [23] after long-term zinc deficiency in rats which causes abnormalities in taste buds ultimately leading to decreased taste sensitivity.…”

Polaprezinc, a zinc compound, is distributed to the lingual epithelium and increases its zinc concentration in zinc-deficient rats

“…It can be expected that tissues with high proliferative activity like epithelium would be susceptible to a lack of zinc. CA has been also identified in saliva and has been shown to be a taste bud growth factor which relates directly to its mechanism of action, while CA is reduced in both saliva and taste buds in zinc deficiency (Thatcher et al 1998;Henkin et al 1999a,b;Kivela et al 1999) In zinc-deficient rats, it was reported that the lingual epithelium has a hypercellular prickle cell layer and marked parakeratosis (Catalanotto and Nanda 1977), along with reduction of the total number and profile area of taste buds (Chou et al 2001). Thus, hypogeusia may be caused by a reduction of taste bud cell turnover, impairment of enzyme activity and various pathological changes.…”

Zinc homeostasis in the brain of adult rats fed zinc-deficient diet

“…Control (zinc-adequate) and zinc-deficient diets, which were prepared as described by Catalanotto and Nanda (1977), were purchased from Oriental Yeast Co. Ltd., Yokohama, Japan. The composition of diet is shown in Table I.…”