Parasympathetic regulation of mitosis induced in rat parotid by dietary change

Mitotic activity of rat parotid was increased from levels near zero to 10-40 mitotic figures per 1,000 acinar cells (mean, 15/1,000) 2 days after glandular activity was increased from less than normal to normal by replacing liquid diet with a diet of solid chow. This frequency greatly exceeded the maximum (1-3/1,000 acinar cells) observed at any time during the diurnal mitotic fluctuations. This mitotic burst was virtually prevented if the auriculotemporal nerve was removed 2 days prior to introduction of solid chow, but was only somewhat reduced when the superior cervical ganglion was removed prior to the dietary substitution. The parasympathetic innervation also was chiefly responsible for the increased cell size that followed reintroduction of solid food.