Influence of naloxone on gastric emptying of solid meals, myoelectrical gastric activity and blood hormone levels in young healthy volunteers

Abstract

There is considerable evidence that opioid mechanisms are involved in the mediation of pyloric motor responses that in turn regulate gastric emptying. The purpose of this randomized, placebo-controlled crossover study was to investigate the effect of naloxone on gastric emptying of a solid meal, gastric myoelectrical activity and the postprandial release of gastrointestinal peptides and neuropeptides in 20 healthy volunteers. Naloxone was administered as an intravenous bolus, followed by continuous infusion according to an intravenous dosing nomogram. Gastric emptying time was evaluated by scintigraphy and gastric myoelectrical activity was evaluated by cutaneous electrogastrography. Naloxone did not significantly alter gastric half-emptying time and postprandial dominant gastric electrical frequency compared with placebo. It also did not significantly change the plasma levels of several peptide hormones with the exception of neuropeptide Y, which was significantly increased (P = 0.001). In conclusion, in doses that influence human intestinal motility, naloxone had no effect on gastric motility and release of several peptide hormones in healthy male volunteers. The importance of the isolated increased neuropeptide Y plasma level needs further investigation.

Roles of putative neurotransmitters in the regulation of gastric and intestinal slow waves in conscious dogs

“…Exogenously administrated opiate analogs induced gastric slow‐wave rhythm disruption in animal and human models, which was blocked by the opiate antagonist naloxone 47 . However, a clinical study demonstrated that naloxone did not alter gastric slow waves measured by electrogastrography in healthy humans 52 . It should be noted that these previous findings were based on electrogastrography, an attractive non‐invasive method of detecting gastric slow waves using abdominal surface electrodes 28 .…”

“…47 However, a clinical study demonstrated that naloxone did not alter gastric slow waves measured by electrogastrography in healthy humans. 52 It should be noted that these previous findings were based on electrogastrography, an attractive noninvasive method of detecting gastric slow waves using abdominal surface electrodes. 28 In the present study, gastric slow waves were assessed using internal serosal electrodes, a more direct and reliable method.…”

Role of endogenous opioids in the control of gastric sensorimotor function

“…12,16 Studies of the effect of naloxone on gastric emptying yielded conflicting results. [17][18][19][20][21][22][23] The role of opioids in the control of the gastric accommodation response has not yet been directly addressed.…”

The effect of naloxone‐3‐glucuronide on colonic transit time in healthy men after acute morphine administration: a placebo‐controlled double‐blinded crossover preclinical volunteer study

“…Scintigraphy is an adequate method to measure GI motility in the upper and lower GI tract as we and others already published 17–23 …”

“…NX3G = 0.16 mg/kg (an equivalent dose of 0.1 mg/kg of NX) or PL was administered orally. The chosen doses of medication had already been used in several previous studies and clinical settings 2, 9, 17 . The sequence of administering the various medications and placebo was determined randomly.…”