Decreased UCP2 mRNA expression in rat stomach following vagotomy: novel role for UCP2 as free radical scavenger in the stomach?

Uncoupling protein 2 (UCP2) is a protein, located in the inner mitochondrial membrane, which dissipates the proton gradient of this membrane and uncouples respiration from oxidative phosphorylation. We found, by in situ hybridisation, UCP2 mRNA to be located in the proliferating zone of the mucous neck cells in the fundus part of the rat stomach. We also found that UCP2 expression in fundus was significantly decreased after seven days of vagotomy. Furthermore, we found manganese-containing superoxide dismutase (SOD2), in fundus, to be down-regulated in a way similar to UCP2. The amount of ATP was significantly decreased following vagotomy. It is concluded that UCP2 in the gastro-intestinal tract is regulated through vagal innervation and suggested to act as a free radical scavenger.