Interactions between cytochrome system and H ion secretion in bullfrog gastric mucosa

Abstract

Relationships between oxidation-reduction states of cytochromes and active H ion secretion have been examined in isolated frog gastric mucosa. The tissue contains a normal complement of cytochromes, flavoprotein, and NAD [nicotinamide adenine dinucleotide]. Changes in the rate of H ion transported were found to result in changes in the oxidation-reduction state of cytochrome c. The results indicated that acid secretion was closely associated with a process that caused cytochrome c to shift to a more reduced steady state. There appeared to be an excess of cytochrome c in the mucosa relative to the amounts usually found in mitochondrial preparations, and it seems likely that there is extramitochondrial cytochrome c which may be specifically involved in the transfer of energy and H ions.