Regulation of neural responses in the canine pyloric sphincter by opioids

Opiates, the Pylorus, and Gastroparesis

“…Regulation of postjunctional responses to enteric nerve stimulation by opioids was characterized in canine pyloric muscles. 21 Methionineenkephalin and [D-Ala, 20 D-Leu 10 ] enkephalin (DADLE) inhibit both cholinergic excitatory and nitrergic inhibitory junction potentials (Figure 1B). 21 Effects of endogenous opiates were also detected and were characterized by reduced nitrergic inhibition.…”

“…21 Methionineenkephalin and [D-Ala, 20 D-Leu 10 ] enkephalin (DADLE) inhibit both cholinergic excitatory and nitrergic inhibitory junction potentials (Figure 1B). 21 Effects of endogenous opiates were also detected and were characterized by reduced nitrergic inhibition. These results supported the conclusion that endogenous opiate peptides participate in regulation of pyloric contraction under some circumstances (such as duodenal acidification 22 ) and that exogenous opioid compounds might interfere with normal neural regulation of the pylorus and, thus, they are likely to affect gastric emptying.…”