Does gastric aminopyrine clearance reflect gastric mucosal blood flow or parietal cell function?

Gastric aminopyrine clearance was measured in human volunteers and dogs with untreated basal secretion, in human volunteers and dogs treated with secretory inhibitors, in dogs treated with histamine, and in patients with pernicious anaemia. When aminopyrine was given as a bolus to man or dog, aminopyrine clearance and the ratio aminopyrine concentration in gastric juice/aminopyrine concentration in plasma showed an initial peak two to three times over steady state levels. When aminopyrine was given with histamine, the peaks were even higher. No peaks occurred when an aminopyrine bolus was given to patients with pernicious anaemia or to healthy volunteers treated with secretory inhibitors. The height of the peaks paralleled the acid secretory rate. The peaks may best be explained by aminopyrine accumulation in the parietal cells and washing out of aminopyrine by volume flow. The steady state levels might reflect both parietal cell function and gastric mucosal blood flow.