Time-course of mitochondrial and cytoplasmic oxidoreduction state of rat liver following an intravenous glucose load.
Changes in mitochondrial and cytoplasmic oxidoreduction states after an intravenous glucose infusion were studied in the freeze-clamped liver of normal and alloxan-induced diabetic rats. In normal rats the mitochondrial oxidoreduction state (NAD+/NADH) increased maximally at 5 min after glucose infusion (p less than 0.001) and then returned to about normal fasting level at 30 min later. The cytoplasmic oxidoreduction state reached its peak level at 30 min after glucose infusion (p less than 0.001). A clear temporal correlation was observed between the mitochondrial oxidoreduction state and insulin and glucose levels in plasm. On the other hand, in alloxan-induced diabetic rats no changes were detected in the oxidoreduction state os either mitochondria or cytoplasm in response to glucose infusion. Therefore the increase in portal insulin level as it occurs in response to the rise of blood glucose may play a role in the shift of the mitochondrial oxidoreduction state to its more oxidized state. This shift seems likely to be due to an accelerated removal of the reducing equivalents through electron transfer by the respiratory chain.
D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D003593:Cytoplasm / Q000187:drug effects* / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism; D005947:Glucose / Q000008:administration & dosage / Q000494:pharmacology*; D006884:Hydroxybutyrate Dehydrogenase / Q000032:analysis; D007263:Infusions, Parenteral; D007328:Insulin / Q000097:blood; D007773:Lactates / Q000032:analysis; D008297:Male; D008930:Mitochondria, Liver / Q000187:drug effects* / Q000378:metabolism; D009243:NAD / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects*; D051381:Rats; D013997:Time Factors
D001786:Blood Glucose; D007328:Insulin; D007773:Lactates; D009243:NAD; D006884:Hydroxybutyrate Dehydrogenase; D005947:Glucose