Effect of truncal vagotomy on parietal cell mass and antral gastrin cell mass in dogs.

Vagotomy is known to reduce acid secretion and to increase serum gastrin concentrations. However, there is minimal information on the effect of vagotomy on parietal cell mass or gastrin cell mass. Basal and maximal acid secretions and fasting serum gastrin concentrations were measured in 22 gastric fistula dogs with pyloromyotomy before and up to 56 days following complete bilateral truncal vagotomy (n = 11) or sham vagotomy (n = 11). Dogs underwent total gastrectomy on postoperative days 9 (n = 5 per group) or day 56 (n = 6 per group). Parietal cells were stained with Luxol fast blue and parietal cell mass determined with computer-assisted histomorphometry. Parietal cell mass averaged 10.68 +/- 0.90 billion in control dogs and correlated significantly with maximal acid output (r = 0.76; P less than 0.01). Vagotomy reduced maximal acid output by 40%-50% (P less than 0.001) but had no significant effect on parietal cell mass (8.99 +/- 1.00 billion). Vagotomy increased serum gastrin concentrations significantly, but antral gastrin cell mass in vagotomized dogs (5.66 +/- 1.00 million) was not significantly different than that in control dogs (4.74 +/- 0.50 million). Thus, vagotomy did not lead to parietal cell hypoplasia or gastrin cell hyperplasia despite profound alterations in parietal cell and gastrin cell function.