title: Abdominal surgery induces Fos immunoreactivity in the rat brain.
abstract: Previous neuropharmacological studies indicate that brain peptides are involved in mediating gastric stasis induced by abdominal surgery. Central pathways activated by abdominal surgery were investigated in the rat by using Fos protein as a marker of neuronal activation. Abdominal surgery (laparotomy alone or combined with cecal manipulation) was performed under brief enflurane anesthesia (7-8 minutes), and 1 hour later rats were killed and brains processed for Fos immunoreactivity. Double labeling with Fos and arginine vasopressin, oxytocin, or tyrosine hydroxylase antibodies was also performed. Abdominal surgery induced Fos staining in the nucleus tractus solitarii, paraventricular and supraoptic nuclei of the hypothalamus, locus coeruleus, and ventrolateral medulla. After abdominal surgery, 18-25% of vasopressin and 18-33% of oxytocin-labeled cells were found to be Fos positive in the paraventricular nucleus and 15% of activated cells in the nucleus tractus solitarii were positive for tyrosine hydroxylase immunoreactivity. Enflurane alone induced c-fos expression in the same brain area; however, the number of Fos-positive cells and double-labeled cells were decreased two- to fivefold and three- to eightfold, respectively, compared with the abdominal surgery groups. These data show that abdominal surgery induced activation of specific hypothalamic, pontine, and medullary neurons. These findings may have implications for the understanding of central mechanisms involved in mediating gastric ileus following abdominal surgery.
authors.affiliation: CURE/UCLA Digestive Disease Center, VA Wadsworth Medical Center, Department of Medicine 90073.
authors.forename: B
authors.initials: B
authors.lastname: Bonaz
authors.forename: V
authors.initials: V
authors.lastname: Plourde
authors.forename: Y
authors.initials: Y
authors.lastname: Taché
mesh_terms: D000005:Abdomen / Q000601:surgery*; D000818:Animals; D015415:Biomarkers / Q000737:chemistry; D001923:Brain Chemistry / Q000502:physiology*; D001931:Brain Mapping; D007124:Immunoenzyme Techniques; D008297:Male; D009419:Nerve Tissue Proteins / Q000032:analysis; D009434:Neural Pathways / Q000737:chemistry; D010286:Paraventricular Hypothalamic Nucleus / Q000737:chemistry; D016760:Proto-Oncogene Proteins c-fos / Q000032:analysis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017552:Solitary Nucleus / Q000737:chemistry; D013495:Supraoptic Nucleus / Q000737:chemistry
chemical_list: D015415:Biomarkers; D009419:Nerve Tissue Proteins; D016760:Proto-Oncogene Proteins c-fos