Studies on the pathogenesis and subclassification of duodenal ulcer （Du） by the determination of serum pancreatic polypeptide （PP）

This study was undertaken to investigate the serum PP values, which has been considered as the indicator of vagal tone, by radioimmunoassay （RIA） in 83 cases DU aged 18-60 years and 72 normal individuals as age-matched control. The mean basal levels of PP in DU groups were significantly higher, and were normalized after the suppression by atropine. However, the elevated basal PP values were noticed only in 35% of cases of DU. These findings suggest that vagal hyperfunction is only resposible for the development of DU in some patients but not all. It seems reasonable to classify.The regression equation y=0.6X-25.3 may be useful in differentiating whether an elevated basal PP is caused by increased vagal tone.The determination of serum basal PP values combined with atropine suppression test may roughly reflect the capacity of the stimulated acid secretion in DU. This study also shows that the vagal activity which is of most importance in regulating parietal cell secretion and the hypersecretion of gastric acid in DU is mainly governed by cholinergic vagus system.