Evaluation of a short-time, oxygen carrier-free perfusion model in rat liver: mitochondrial energy metabolism and insulin effect.
Livers of rats fasted for 18 hr were perfused for 60 min at 37, 35, and 32 degrees C in a simple noncirculating system with a carbogen (95%, 5% CO2) equilibrated, oxygen carrier-free, glucose-containing (200 mg X dl-1) cristalloid perfusate (pH 7.4, 280 mosmol X kg-1) without or with the addition of insulin (10 U X hr-1), and analyzed for tissue ATP, ADP, AMP, acetoacetate, and beta-hydroxybutyrate as well as for parameters of the energy metabolism of isolated mitochondria. Perfusion without insulin at 37 degrees C caused significant alterations: ATP and total adenine nucleotides (TAN) dropped to 62 and 74% of the control values (3.33 and 4.57 mumol X g-1), respectively. The energy charge potential ECP decreased from 0.842 to 0.713. Also, the mitochondrial phosphorylation rate (PR), the respiratory control ratio (RC), and the state 3 respiration rate (ST 3) were significantly depressed to 62, 54, and 72% of the control values. Perfusion with insulin maintained a normal metabolic pattern: ATP 105%, TAN 97%, ECP 0.877, PR 94%, RC 69%, and ST 3 105%. The metabolic deterioration during insulin-free perfusion was decreased at 35/32 degrees C: ATP 67/82%, PR 72/95%, RC 74/87%. At 35 degrees C, insulin ameliorated the metabolic pattern, but normal ranges were no longer reached. At 32 degrees C, insulin had no effect.
D020155:3-Hydroxybutyric Acid; D000090:Acetoacetates / Q000378:metabolism; D000227:Adenine Nucleotides / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D004734:Energy Metabolism; D005069:Evaluation Studies as Topic; D006885:Hydroxybutyrates / Q000378:metabolism; D007328:Insulin / Q000494:pharmacology*; D008099:Liver / Q000378:metabolism*; D008297:Male; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism*; D010477:Perfusion / Q000379:methods*; D010827:Physiology / Q000295:instrumentation; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
D000090:Acetoacetates; D000227:Adenine Nucleotides; D006885:Hydroxybutyrates; D007328:Insulin; D000255:Adenosine Triphosphate; D020155:3-Hydroxybutyric Acid