title: Hemorrhagic shock impairs myocardial cell volume regulation and membrane integrity in dogs.
abstract: An in vitro myocardial slice technique was used to quantitate alterations in cell volume regulation and membrane integrity after 2 h of hemorrhagic shock. After in vitro incubation in Krebs-Ringer-phosphate medium containing trace [14C]inulin, values (ml H2O/g dry wt) for control nonshocked myocardial slices were 4.03 +/- 0.11 (SE) for total water, 2.16 +/- 0.07 for inulin impermeable space, and 1.76 +/- 0.15 for inulin diffusible space. Shocked myocardial slices showed impaired response to cold incubation (0 degrees C, 60 min). After 2 h of in vivo shock, total tissue water, inulin diffusible space, and inulin impermeable space increased significantly (+19.2 +/- 2.4, +8.1 +/- 1.9, +34.4 +/- 6.1%, respectively) for subendocardium, whereas changes in subepicardium parameters were minimal. Shock-induced cellular swelling was accompanied by an increased total tissue sodium, but no change in tissue potassium. Calcium entry blockade in vivo (lidoflazine, 20 micrograms X kg-1 X min-1 during the last 60 min of shock) significantly reduced subendocardial total tissue water as compared with shock-untreated dogs. In addition, calcium entry blockade reduced shock-induced increases in inulin impermeable space and inulin diffusible space. In vitro myocardial slice studies confirm alterations in subendocardial membrane integrity after 2 h of in vivo hemorrhagic shock. Shock-induced abnormalities in myocardial cell volume regulation are reduced by calcium entry blockade in vivo.
mesh_terms: D000758:Anesthesia; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000648:ultrastructure*; D002463:Cell Membrane Permeability; D003326:Coronary Circulation / Q000187:drug effects; D004285:Dogs; D005260:Female; D006439:Hemodynamics; D007424:Intracellular Fluid; D007444:Inulin / Q000378:metabolism; D008013:Lidoflazine / Q000494:pharmacology; D008297:Male; D009206:Myocardium / Q000166:cytology*; D012771:Shock, Hemorrhagic / Q000473:pathology*; D013696:Temperature
chemical_list: D007444:Inulin; D008013:Lidoflazine; D002118:Calcium