title: Effects of ischemia and dimethyl sulfoxide on equine jejunal vascular resistance, oxygen consumption, intraluminal pressure, and potassium loss.
abstract: Physiologic effects of 1 hour of ischemia and 1 hour of reperfusion on equine jejunum and protective effects of systemic administration of dimethyl sulfoxide (DMSO, 1 g/kg of body weight) were investigated in 18 ponies, using neurally intact segments of jejunum perfused at constant flow with heparinized blood. Ponies were allotted to 4 groups: group 1, saline solution administered (control, n = 3); group 2, DMSO administered (DMSO, n = 3); group 3, ischemia induced and saline solution administered (ischemia, n = 6); and group 4, ischemia induced and DMSO administered (ischemia-DMSO, n = 6). Intestinal vascular resistance (R, mm of Hg/ml/min/100 g), oxygen consumption (VO2, ml/min/100 g), frequency and amplitude of rhythmic changes in intraluminal pressure, intestinal compliance (C, ml/mm of Hg), and arteriovenous potassium concentration difference (delta AV [K+], mEq/L) were determined and compared with stable preischemic values within groups. There were no significant changes in any variable in ponies of groups 1 or 2. In ponies of group 3, significant (P less than or equal to 0.05) changes included: an initial increase in R during reperfusion, followed by a decrease to values below preischemic values by 15 minutes of reperfusion; decreased VO2 during the entire reperfusion period; increased amplitude of rhythmic contractions during initial reperfusion; decreased frequency of rhythmic contractions during ischemia; and increased delta AV [K+] during initial reperfusion. Changes in ponies of group 4 were identical to changes in ponies of group 3, with the exception that DMSO administration prevented the decrease in R during reperfusion.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Large Animal Clinical Sciences, Michigan State University, East Lansing 48824.
authors.forename: W A
authors.initials: WA
authors.lastname: Arden
authors.forename: J A
authors.initials: JA
authors.lastname: Stick
authors.forename: A H
authors.initials: AH
authors.lastname: Parks
authors.forename: C C
authors.initials: CC
authors.lastname: Chou
authors.forename: R F
authors.initials: RF
authors.lastname: Slocombe
mesh_terms: D000818:Animals; D004121:Dimethyl Sulfoxide / Q000627:therapeutic use*; D005769:Gastrointestinal Motility; D006734:Horse Diseases / Q000188:drug therapy / Q000503:physiopathology*; D006736:Horses; D007511:Ischemia / Q000188:drug therapy / Q000503:physiopathology / Q000662:veterinary*; D007583:Jejunum / Q000098:blood supply* / Q000503:physiopathology; D010101:Oxygen Consumption; D011188:Potassium / Q000378:metabolism; D011312:Pressure; D014655:Vascular Resistance
chemical_list: D011188:Potassium; D004121:Dimethyl Sulfoxide