Morphometric studies of parietal cells in cats before and after lesser-curvature seromyotomy

A modified, highly selective vagotomy-seromyotomy of the lesser curvature of the stomach was performed on five groups of cats. The horseradish peroxidase (HRP) tract-tracing method was used to detect the regeneration or reinnervation of vagal nerve branches. Morphological changes to the parietal cells and to the gastric mucosa were also examined by light and electron microscopy. Following surgery, the cats were sacrificed at the fourth, eighth, twelfth, sixteenth and the twentieth week. At the sixteenth week, partial regeneration of vagal nerve branches was found. Between the fourth and the twelfth week there was a significant increase in the number of parietal cells per 0.1 mm-wide of mucosa column and in the volume fraction of the mucosa made up of parietal cells. Of the four types of parietal cells, "stimulated", "partially stimulated", "returning" and "resting", the resting type was predominant after seromyotomy, especially between the fourth and the twelfth week. Based on the above observation, we concluded that the modified lesser-curvature seromyotomy depresses the function and responsiveness of the parietal cells despite an increase in their number and in their volume fraction.