Discussion of “Blood Flow and Secretion in the Stomach”

Abstract

As Dr. Jacobson has quite correctly emphasized, an answer to the question of a possible relationship between blood flow and secretion in glandular organs necessitates a knowledge of the local blood flow to the secreting portion of those organs-in the case of the stomach, the mucosa of the corpus. A valid method for estimating corpus mucosal blood flow, as distinct from total gastric flow, is therefore essential. To date, this problem has been approached in two ways. One is that of Jacobson and his collaborators,l the measurement of aminopyrine clearance. The other has been made by Delaney and myself,2.3 the measurement of mucosal radiopotassium (K42) clearance. Since these two techniques are based on quite different assumptions, agreement of the results obtained with them can give us some confidence in the validity of both. A few minutes spent in such a comparison seem worthwhile. Comparison must be made with stimulated stomachs, since the aminopyrine technique is not applicable to the nonsecreting mUCO$a. During histamine stimulation, the two techniques have given similar results. With intravenous infusion of this agent for 15 to 20 min at 1 }log per min per Kg of body weight, there is an increase in total flow, most of which goes to the mucosa. Nonmucosal flow is changed very little. Mucosal perfusion with both methods is about 1.5 ml per min per g. With graded sub maximal doses, Jacobson found an increase in mucosal flow only, not in total flow. We have not performed a similar experiment and so cannot compare. With the use of secretory inhibitors, some discrepancies unfortunately have appeared. With pitressin, both techniques showed a profound depression of mucosal