Protofibril formation: decreased total glutathione concentration as an early indicator of neuron damage in the brainstems of Wistar rats treated with rotenone [version 1; peer review: 2 approved with reservations]

Background: Rotenone treatment causes oxidative stress in neurons and forms the basis of animal models of Parkinson's disease. The reduced form of glutathione is predicted to detoxify rotenone from neurons in the brainstem. This study aims to measure the concentration of total glutathione and analyze the formation of protofibril in the brainstem of Wistar rats treated with rotenone. Methods: Seventy-two male Wistar rats aged 8–9 weeks weighing 200–250 g were divided into two investigations: total glutathione determination and protofibril analysis. The independent variables were treatment group, observation time, and location in the brainstem. The dependent variables were the concentration of total glutathione and protofibril density. Results: The concentration of total glutathione was not significantly different among treatment groups (p: 0.084), observation time (p: 0.608), or the location in the brainstem (p: 0.372). Protofibril density was different in the treatment groups (p: 0.001), observation time (p: 0.001), and between the upper and lower brainstem (p: 0.001). Rotenone treatment subcortically induced the concentration of total glutathione in the brainstem to decrease, but protofibril density tended to increase. Conclusions: The total glutathione concentration is inversely proportional to protofibril density. Total glutathione might be an early marker of neuronal damage.