The absorption and excretion of water by the mammal. Part I.—The relation between absorption of water and its excretion by the innervated and denervated kidney

Abstract

When a large volume of water is given by mouth to the normal dog, there is usually a delay of about 10 minutes before the kidney begins to respond, and of about 50 minutes before the response reaches its maximum intensity, fig. 1. It was with the main object of apportioning this delay between the processes involved in the transport of the water, and of determining the relationship between the water-load of the body and the rate of excretion of water by the kidneys, that the work described in this paper was undertaken. As will be seen later, we have used a method which, in allowing the secretion of one kidney to be collected separately from that of the other, has offered the means of answering cognate questions involving the influence of some factors of physiological significance on the response of the kidney to water-ingestion. To these questions consideration will be given in part II, where all the facts in their theoretical interrelationship will be discussed. The delay referred to above, might be allocated theoretically to one or more of several sites and functions. First, the water might be retained in the stomach, its passage into the small gut being accurately and rapidly reflected in its excretion by the kidney. Second, absorption itself might be the principal seat of delay. Third, there might be a latent period between absorption and excretion, the spatial representation of the events occurring in this time not being, of necessity, restricted to the kidneys.