Study of isolated mitochondria incubated with labelled and non-labelled alloxan, with regard to intramitochondrial concentrations of reduced glutathione and inorganic phosphate

Abstract

Isotope technique and determination of the intramitochondrial concentration of GSH were used with the aim of studying the uptake of alloxan in isolated mouse mitochondria. A significantly decreased concentration of GSH was observed in mitochondria from liver and pancreas incubated with alloxan. This effect was significantly more marked in mitochondria depleted of Pi. Increased radioactivity was found in isolated mitochondria from liver, exocrine pancreas and endocrine pancreas incubated with 14C-2-alloxan. Even this effect was significantly more marked in Pi depleted mitochondria. Isolated liver mitochondria of the KsJ-strain of C57BL-mice possessed a significantly lower concentration of endogenous Pi than those of the 6J-strain. The findings support the view that alloxan can pass across the inner mitochondrial membrane, and suggest that the intramitochondrial concentration of Pi is one of the factors which has an influence on the uptake of alloxan in isolated mouse mitochondria.