Reductive stress in mitochondria isolated from the carotid body of type 1 diabetic male Wistar rats.

Abstract

The carotid body (CB) senses changes in arterial O₂ partial pressure (pO₂) and glucose levels; therefore, it is key for the detection of hypoxia and hypoglycemia. The CB has been suggested to detect pO₂ through an increase in reactive oxygen species (ROS) in the mitochondria. However, the mechanism protecting the chemoreceptor cells and their mitochondria from ROS and hyperglycemia is poorly understood. Here we measured glutathione levels in CB mitochondria of control and in streptozotocin (STZ)-induced type 1 diabetic male Wistar rats. We found a dramatic reduction in total glutathione from 11.45 ± 1.30 μmol/mg protein in control rats to 1.45 ± 0.31 μmol/mg protein in diabetic rats. However, the ratio of reduced to oxidized glutathione, a measure of the redox index, was increased in diabetic rats compared to controls. We conclude that the mitochondria of CB chemoreceptor cells in type 1 diabetic male Wistar rats were likely under glutathione-reducing stress.