Journal of Applied Physiology, Vol 39, Issue 4 519-522, Copyright © 1975 by American Physiological Society
Evaluation of a reservoir in the main excretory duct of rat submaxillary gland
L. H. Schneyer and R. F. Flatland
Cannulation of salivary gland main excretory duct at its oral opening is
routinely used for collecting fluid, in situ, from the luminally perfused
duct, or saliva from the stimulated gland. For perfusion of the main
excretory duct, in situ, or for saliva collection, rat submaxillary gland
is often the organ of choice, since electrolyte transport occurs at high
rates both in the whole gland and in the main excretory duct. Recently, it
has been reported that there is a pouchlike dilatation of the main
excretory duct at its oral end, and that this dilatation may serve as a
fluid reservoir. Because of possible effects of such a reservoir on
measurements of electrolyte transport by the whole gland or the main duct
segment, the size and form of the reservoir have now been examined. For
this, techniques of histology, radiography, and microcatherization were
employed. It was found that, while the functional volume of the reservoir
exceeds that of the main duct proper, the time needed for displacement of
reservoir fluid by perfusate or saliva would probably be only on the order
of 1-3 min at higher rates of saliva or perfusate flow. Therefore, if
adequate allowance is made for equilibration time, collection of saliva or
luminal perfusate by oral cannula seems justified.
