9318753 Yokota This project investigates the regulation of the reptilian kidney by neural and hormonal mechanisms, and uses the snake kidney as a model for the development and application of methods to assess vertebrate renal function in fine detail, in time and space. The ophidian kidney allows the analysis of renal function at whole animal, isolated organ and individual functional unit (nephron) levels, and because of its unique morphology permits the simultaneous application of several microtechniques which provide unprecedented resolution of function of filtering units of the kidney, the glomeruli. Using videomicroscopic and micropuncture methods the blood flow in single glomerular microvessels, which supply the glomeruli, and glomerular capillary blood pressures can be measured continuously. These measurements allow us to define the state of glomerular function and the mechanisms for modulation of glomerular functional by neural and hormonal factors. Studies on whole kidney function will define the functional range for the control of renal function by vasoactive hormones. And studies on intact animals will define the physiological range of endogenous neural and hormonal effectors in controlling normal renal function and in regulating responses to changes in physiological state. Integration of these studies will provide a more detailed picture of vertebrate renal regulation than has been heretofore possible and may serve to illuminate general principles for the regulation of renal function for all vertebrate kidneys. ***
