Physiological study on the role of zinc enzyme on the improvement of taste disorders

我们已经证实，NaCl的偏好是更大的锌缺乏和低锌大鼠比对照组（锌充足和配对喂养）大鼠喂养4天后。此外，我们还报告说，长期缺锌降低味觉敏感性的水平鼓索神经和NaCl偏好的变化，由于缺锌发生在味觉敏感性下降之前。为了阐明机制增加NaCl的偏好，观察在缺锌和低锌大鼠在喂养的早期阶段，因此，我们研究了锌缺乏对血浆指数（矿物质浓度，pH值，红细胞压积），血压，尿排泄，饮水量和选定的激素的影响。将4周龄雄性Sprague-Dawley大鼠分为缺锌组、低锌组和配对喂养组。在喂养早期，缺锌大鼠血浆钠浓度无明显变化。我们还研究了缺锌对大鼠神经垂体激素的影响，因为脑催产素系统通过影响钠的摄入和排泄来调节钠平衡。因此，即使在喂养4天后，缺锌饲料的喂养仍导致血浆催产素浓度下降。这些结果表明，缺锌的饮食信号可能反映NaCl偏好，可能通过下丘脑-神经垂体系统。

We have confirmed that NaCl preference is greater in the zinc-deficient and low-zinc rats than in the control (zinc-sufficient and pair-fed) rats after 4 days' feeding. Furthermore, we have also reported that long-term zinc deficiency decreases taste sensitivity at the level of the chorda tympani nerve and that the change in NaCl preference due to zinc deficiency occurs before the decrease in taste sensitivity. In order to clarify the mechanism for the increased NaCl preference observed in zinc-deficient and low-zinc rats at an earlier stage of the feeding, we therefore investigated the effects of zinc deficiency on plasma index (mineral concentration, pH, hematocrit), blood pressure, urinary excretion, water intake and selected hormones. Male 4 week-old Sprague-Dawley rats were divided into three groups (zinc-deficient, low-zinc and pair-fed). At an earlier stage of the feeding period, there was no change of plasma sodium concentration in the zinc-deficient rats. We also investigated that the effects of zinc deficiency on neurohypophysial hormones in rats because brain oxytocin system is important for the regulation of sodium balance via effects on sodium intake and excretion. In consequence, the feeding of zinc-deficient diet causes the decrease of plasma oxytocin concentration even after 4 days' feeding. These results suggest that the dietary signal of zinc-deficiency may reflect NaCl preference, possibly through the hypothalamus-neurohypophysial system.