EFFECT OF INPUT PRESSURE AND FLOW ON THE PATTERN AND RESISTANCE TO FLOW IN THE ISOLATED PERFUSED GILL OF A TELEOST FISH

When an isolated gill arch of the marine teleost, Ophiodon elongatus, was perfused under conditions which mimic those present in the intact animal, only two thirds of the gill lamellae were perfused. An increase in either input (afferent) pressure and flow or input pulse pressure caused an increase in the number of lamellae perfused as well as altering the distribution of the efferent outflow between the efferent artery and the venolymphatic drainage of the gill. The gill is compliant and an increase in efferent pressure reduced gill resistance to flow without altering the number of lamellae perfused. In these experiments there was no simple relationship between the number of lamellae perfused and gill resistance. These observations are of importance in the interpretation of results from pharmacological and ion exchange studies of isolated gills as well as indicating how cardiovascular changes could bring about alterations in gill blood flow in the intact fish. © 1979, Springer-Verlag. All rights reserved.