Acid-base status strongly effects many key physiological functions, including enzyme catalysis, ionic balance, membrane transport, and hormone-receptor binding. Our understanding of this critical aspect of physiology is extremely limited. The objective of this study is to develop a model for extracellular (blood) acid-base regulation in an insect, using the locust. The role of the ventilatory and renal system in blood pH regulation will be examined be Dr. Harrison; these two systems dominate exchange of acid-base relevant compounds with the environment. He will assess the role of the renal system using natural (starvation) and artificial acid stresses. Then he will determine the location of acid-base regulatory sites by cannulating individual renal segments. These experiments will be based on micro-electrode, titration, biochemical, and gas sampling techniques. This study will generate the first integrated model of acid-base regulation in an insect, and will provide general insight into the mechanisms used by animals to compensate for physiological stresses.
