title: Glucose and fatty acid oxidation by the in situ dog heart during experimental cooling and rewarming.
abstract: BACKGROUND
  Reduced myocardial function after hypothermia may be metabolic in origin, but the relationship between myocardial metabolism and the various components of hypothermia-mediated dysfunction has not been thoroughly investigated.
  
  
  METHODS
  In the present study we measured myocardial uptake and oxidation of glucose and oleate in mongrel dogs undergoing cooling to 25 degrees C followed by rewarming to 37 degrees C, using radiolabeled substrates.
  
  
  RESULTS
  Segment work index declined from 39.3 +/- 5.1 to 15.1 +/- 2.4 mm Hg in response to cooling from 37 degrees to 25 degrees C and did not recover completely on rewarming (27.2 +/- 4.2 mm Hg, p < 0.05). Oleate uptake declined from 3,251 +/- 619 to 1,043 +/- 356 nmol.min-1.100 g-1 (p < 0.05) when the dogs were cooled from 37 degrees to 25 degrees C. Simultaneously, oxidation rate fell from 1,089 +/- 158 to 354 +/- 83 nmol.min-1.100 g-1 (p < 0.05). On rewarming, oleate uptake was restored to prehypothermic values, whereas its rate of oxidation remained depressed (480 +/- 129 nmol.min-1.100 g-1; p < 0.05). Uptake and oxidation of glucose also declined significantly during cooling. However, both uptake and oxidation of glucose recovered fully on rewarming.
  
  
  CONCLUSIONS
  The results of the present study demonstrate a reduced capacity to oxidize fatty acids by the myocardium during rewarming after hypothermia.
authors.affiliation: Department of Medical Physiology, University of Tromsø, Norway.
authors.forename: T K
authors.initials: TK
authors.lastname: Steigen
authors.forename: T
authors.initials: T
authors.lastname: Tveita
authors.forename: O
authors.initials: O
authors.lastname: Hevrøy
authors.forename: T V
authors.initials: TV
authors.lastname: Andreasen
authors.forename: T S
authors.initials: TS
authors.lastname: Larsen
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D002250:Carbon Radioisotopes; D003326:Coronary Circulation / Q000502:physiology; D004285:Dogs; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005947:Glucose / Q000378:metabolism* / Q000493:pharmacokinetics; D006339:Heart Rate / Q000502:physiology; D007036:Hypothermia, Induced; D007773:Lactates / Q000097:blood; D009200:Myocardial Contraction / Q000502:physiology; D009206:Myocardium / Q000378:metabolism*; D019301:Oleic Acid / Q000378:metabolism* / Q000493:pharmacokinetics; D010084:Oxidation-Reduction; D019275:Radiopharmaceuticals; D017694:Rewarming; D014316:Tritium; D016277:Ventricular Function, Left / Q000502:physiology; D017725:Ventricular Pressure / Q000502:physiology
chemical_list: D001786:Blood Glucose; D002250:Carbon Radioisotopes; D005230:Fatty Acids, Nonesterified; D007773:Lactates; D019275:Radiopharmaceuticals; D014316:Tritium; D019301:Oleic Acid; D005947:Glucose