title: Effect of magnesium on gastrointestinal transit time in normal and diabetic rats: possible mechanism of action.
abstract: BACKGROUND
  Many gastrointestinal complications in diabetes are connected to neurohumoral dysfunction resulting in abnormalities of intestinal motility, secretion and absorption. Minerals have been reported as essential cofactors for basic cellular reactions but there is dearth of information on effect of Magnesium on gastrointestinal transit time (GITT) and the mechanism of action.
  
  
  METHODS
  Sixty male albino Wistar rats (180 - 200g) were grouped into twelve of five animals each. Group 1 (control) received 0.2ml saline. Groups 2-6 were normal rats treated with magnesium sulphate (as magnesium) (500mg/kg), adrenaline (0.5mg/kg), magnesium (500mg/kg) and adrenaline (0.5mg/kg), prazosin (1mg/kg) and both magnesium (500mg/kg) and prazosin (1mg/kg) respectively. Groups 7 - 12 were diabetic rats treated as in groups 1- 6. Diabetes was induced intraperitoneally with alloxan (120mg/kg bwt).
  
  
  RESULTS
  There was significant (p<0.05) reduction in GITT index in normal rats treated with magnesium, prazosin and combination of magnesium and prazosin compared with control. Treatment with adrenaline alone produced significant increase in GITT. However treatment with both magnesium and adrenaline produced significant reduction compared with control. This reduction in GITT was similar to that obtained in magnesium only and prazosin only treated groups. Diabetic groups showed significant reduction in GITT in all treated groups except the adrenaline only treated group which produced significant increase in GITT.
  
  
  CONCLUSIONS
  The significant reduction in GITT produced by magnesium in both normal and diabetic animals was comparable to that produced by prazosin (an á-adrenoceptor antagonist) indicating that magnesium may be inhibiting gastrointestinal smooth muscle contraction through á-adrenoceptor antagonist pathway.
authors.affiliation: Department of Physiology, College of Medicine, University of Ibadan, Ibadan, Nigeria. elolade@yahoo.com
authors.forename: E O
authors.initials: EO
authors.lastname: Adewoye
authors.forename: A O
authors.initials: AO
authors.lastname: Ige
mesh_terms: D058668:Adrenergic alpha-1 Receptor Antagonists / Q000494:pharmacology; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D004837:Epinephrine / Q000494:pharmacology; D005772:Gastrointestinal Transit / Q000187:drug effects* / Q000502:physiology; D008274:Magnesium / Q000494:pharmacology* / Q000502:physiology; D008278:Magnesium Sulfate / Q000494:pharmacology; D008297:Male; D008903:Minerals / Q000494:pharmacology; D011224:Prazosin / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar
chemical_list: D058668:Adrenergic alpha-1 Receptor Antagonists; D000316:Adrenergic alpha-Agonists; D008903:Minerals; D008278:Magnesium Sulfate; D008274:Magnesium; D011224:Prazosin; D004837:Epinephrine