The use of neutral red as a peroperative test of vagal innervation.

The cervical vagi were stimulated electrically in four groups of dogs after the intravenous injection of 10 ml of 1% neutral red. One group had intact vagi, the second group had denervation of the distal parietal cell area of the stomach, the third group proximal parietal cell denervation, and the last group had had a complete transthoracic truncal vagotomy. The area of stomach secreting neutral red was significantly related to the insulin-stimulated acid secretion. This technique may provide the basis of a test of residual vagal innervation of parietal cells during vagotomy operations in man.