Exogenous Neuropeptide Y Blocks Myoelectric Activity in the Upper Gastrointestinal Tract of Starved Dogs: Brain Neuropeptide Y Converts a Fasting Pattern of Myoelectric Activity to a Fed Pattern

Abstract

The effect of intracerebroventricular (ICV) neuropeptide Y (NPY) on the migrating motor complex (MMC) was examined in five starved dogs. Myoelectric activity was recorded using gastric, duodenal, and jejunal electrodes. Intragastric pressure was monitored via a gastric fistula, and ICV injections were given through a cerebroventricular guide. Recordings were made with no ICV injection and before and after 250-μl bolus injections of vehicle as control (0.1% dog serum albumin in saline) or 500 pmol/kg NPY. The mean interval between MMCs was 98 ± 10 min without ICV injection and 96 ± 7 min after control solution. After ICV injection of NPY no further MMCs were recorded in any dog, even though the study was continued for a minimum of 3.5 h. Instead, the myoelectric pattern became indistinguishable from that in fed dogs. We conclude that central NPY plays a role in modulation of upper gastrointestinal myoelectric activity. This may reflect a central regulatory role for NPY in the coordination of feeding.

Key Words:

• Fed state
• gastrointestinal motility
• myoelectric activity
• neuropeptide Y
• starved state