Insect Acid-Base Regulation

小行星9317784 pH值的调节是生物体内平衡最关键的方面之一。 虽然酸碱状态影响各种各样的细胞过程，包括酶催化，离子平衡，膜运输，和昆虫受体相互作用，我们的知识在这方面的昆虫生理学是相当有限的。 哈里森博士先前的研究表明，蝗虫对细胞外pH值的调节非常密切，饮食、饥饿或注射盐酸导致的酸碱负荷会被排出体外。 拟议研究的一个主要目标是确定负责调节酸碱负荷排泄的消化道/后肠复合体的特定区域。 这项研究还将测试中肠酸碱分泌的变化是否可以直接由酸碱状态的变化引起。 一般认为（在昆虫和哺乳动物中）铵的排泄在功能上等同于酸的排泄。 然而，这一假设从未在昆虫中直接进行过测试，最近在哺乳动物中进行了广泛的辩论。 拟议的研究将测试蝗虫后肠的氨排泄是否在功能上等同于以简单、直接的方式分泌酸。 总之，这些实验将为昆虫长期酸碱调节的最重要机制提供第一个生物模型。 ***

9317784 Harrison Regulation of pH is one of the most critical aspects of organismal homeostasis. Although acid-base status affects a wide variety of cellular processes, including enzyme catalysis, ionic balance, membrane transport, and hormone-receptor interactions, our knowledge of this aspect of insect physiology is quite limited. Previous research by Dr. Harrison has shown that locusts regulate extracellular pH quite closely, and that acid- base loads resulting from diet, starvation, or injections of HCl are excreted. A major goal of the proposed research is to determine the specific region(s) of the alimentary canal/hindgut complex responsible for the regulated excretion of acid-base loads. This research will also test whether changes in the secretion of acid-base by the midgut can be directly induced by changes in acid-base status. It is generally assumed (in insects and mammals) that excretion of ammonium is functionally equivalent to acid excretion. However, this assumption has never been tested directly in insects, and recently has been extensively debated for mammals. The proposed study will test whether ammonium excretion by the hindgut of locusts is functionally equivalent to acid secretion in a simple, direct manner. Together, these experiments will provide the first organismal model of the most important mechanisms of long-term acid-base regulation in insects. ***