Effect of selective gastric intrinsic denervation on gastric motility in turkeys.

The effect of selectively denervating portions of the myenteric plexus on gastroduodenal (GD) motility was examined in domestic turkeys (Meleagris gallopavo). The neural network beneath the lateral or medial side of the isthmus between the glandular stomach and the muscular stomach was denervated by application of 1% benzalkonium chloride (BC). Image intensification radiology (IIR) was performed postsurgically on the research subjects to observe GD contractions and to analyze aberrations. Two trials were performed. The first employed temporal controls by checking GD motility in all treated birds before and after BC had taken effect. The second trial controlled for the trauma associated with the surgical procedure by applying 0.9% saline solution in lieu of BC in four turkeys. The normal GD contractions sequence as confirmed by these controls was thin muscle contraction, duodenal contraction and outflow, thick muscle contraction, and, finally, glandular stomach contraction. Ablation of the nerves beneath the medial or lateral side of the isthmus resulted in the same abnormality in GD motility, namely a lack of thick muscle contractions. These results indicate that the entire myenteric plexus associated with the isthmus must remain intact for proper GD motility to take place. Furthermore, it can be inferred that initiation and regulation of the thick muscle pair acts via nerves encircling the isthmus. Secondary regulatory mechanisms controlling GD motility may exist and should be tested through future investigation.