Neural mechanisms involved in the delay of gastric emptying and gastrointestinal transit of liquid after thoracic spinal cord transection in awake rats

Auton Neurosci. 2001 Feb 20;87(1):52-8. doi: 10.1016/s1566-0702(00)00261-7.

Abstract

Spinal cord transection (SCT) delays gastric emptying (GE), and intestinal and gastrointestinal (GI) transit of liquid in awake rats. This study evaluates the neural mechanisms involved in this phenomenon. Male Wistar rats (N = 147) were fasted for 16 h and had the left jugular vein cannulated followed by laminectomy or laminectomy + complete SCT between T4 and T5 vertebrae. The next day, a test meal (1.5 ml of a phenol red solution, 0.5 mg/ml in 5% glucose) was administered by gavage feeding and 10 min later cervical dislocation was performed. Dye recovery in the stomach, and proximal, mid and distal small intestine was determined by spectrophotometry. SCT inhibited GE and GI transit since it increased gastric recovery by 71.3% and decreased mid small intestine recovery by 100% (P < 0.05). Subdiaphragmatic vagotomy, celiac ganglionectomy + section of the splanchnic nerves, i.v. hexamethonium (20 mg/kg) or yohimbine (3 mg/kg) prevented the development of the SCT effect on GE and GI transit. Pretreatment with i.v. naloxone (2 mg/kg), L-NAME (3 mg/kg) or propranolol (2 mg/kg) was ineffective. Bilateral adrenalectomy or guanethidine (10 mg/kg) increased the magnitude of the GE inhibition, while i.v. prazosin (1 mg/kg) or atropine (0.5 mg/kg) decreased the magnitude but did not abolish the GE inhibition. In summary, the inhibition of GI motility observed 1 day after thoracic SCT in awake rats seems to involve vagal and possibly splanchnic pathways.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autonomic Nervous System / drug effects
  • Autonomic Nervous System / pathology
  • Autonomic Nervous System / physiopathology*
  • Cardiovascular Physiological Phenomena / drug effects
  • Digestive System / drug effects
  • Digestive System / innervation*
  • Digestive System Physiological Phenomena*
  • Ganglia, Sympathetic / physiology
  • Ganglia, Sympathetic / surgery
  • Ganglionectomy / adverse effects
  • Gastric Emptying / drug effects
  • Gastric Emptying / physiology*
  • Gastrointestinal Diseases / drug therapy
  • Gastrointestinal Diseases / etiology*
  • Gastrointestinal Diseases / physiopathology*
  • Gastrointestinal Motility / drug effects
  • Gastrointestinal Motility / physiology*
  • Indicators and Reagents / pharmacokinetics
  • Male
  • Phenolsulfonphthalein / pharmacokinetics
  • Rats
  • Rats, Wistar
  • Spinal Cord / pathology
  • Spinal Cord / physiopathology*
  • Spinal Cord Injuries / complications*
  • Splanchnic Nerves / physiology
  • Splanchnic Nerves / surgery
  • Sympathectomy / adverse effects
  • Thoracic Vertebrae
  • Time Factors
  • Vagotomy / adverse effects

Substances

  • Indicators and Reagents
  • Phenolsulfonphthalein