Effect of vagotomy on the quantitative histological distribution of histamine and histidine decarboxylase in the rat stomach.

Determinations were made of the quantitative histological distribution of histamine and histidine decarboxylase in the body of the glandular stomach of fed and 14-hr fasted rats subjected to pyloroplasty and to pyloroplasty with vagotomy for comparison with untreated rats. Pyloroplasty on fasted rats had no significant effect on the concentration of histamine which was localized predominantly in the chief cell zone. However, the superimposed vagotomy was associated with some increase in the concentration. With the fed rats, the concentration was essentially unchanged from normal in either group of operated animals and it also was about the same as that in the normal fasted group. Histidine decarboxylase activity, which was also localized predominantly in the chief cell zone, underwent an increase in concentration following pyloroplasty of the fasted rats; no additional effect was observed with added vagotomy. The higher concentration of the enzyme activity in the fed rats was markedly further elevated in both groups of operated animals but these groups did not differ significantly from one another. An explanation of the elevation of histidine decarboxylase activity following pyloroplasty requires further investigation, but the lack of effect of the superimposed vagotomy on the enzyme activity would appear to rule out direct vagal control as the sole factor in determining the enzyme function at this site.