Desflurane affords greater protection than halothane in the function of mitochondria against forebrain ischemia reperfusion injury in rats.

Abstract

Halothane and desflurane have been shown to attenuate neuronal injury; however, the effects of these anesthetics on mitochondria are unclear. We investigated whether halothane and desflurane affect the function of mitochondria after cerebral ischemia in rats. Forty male Wistar rats were randomly divided into four groups (n = 10 each): sham group; 1.5 minimal alveolar concentration (MAC) halothane group; 1.0 MAC desflurane; and 1.5 MAC desflurane group. Forebrain ischemia was induced after 40-min inhalation of 1.5 MAC halothane, 1.0 MAC or 1.5 MAC desflurane by clamping the bilateral common carotid arteries and decreasing arterial blood pressure. After isolation of the brain mitochondria, mitochondrial membrane permeability was assayed spectrophotometrically with 40-200 microM Ca(2+), and mitochondrial membrane potentials were measured by a fluorospectrophotometer with the addition of rhodamine 123. The activities of mitochondrial respiratory chain complexes were also assayed spectrophotometrically. The results showed obvious mitochondrial swelling, loss of membrane potential with the addition of Ca(2+), and inhibition of the activities of complexes I + III and IV after forebrain ischemia reperfusion injury. Compared with the 1.5 MAC halothane group, 1.0 and 1.5 MAC desflurane reduced mitochondrial swelling by 23.9% (P < 0.001) and 23.2% (P < 0.001), whereas membrane potential dissipation was suppressed by 22.4% (P = 0.013) and 20.4% (P = 0.027). The activities of complexes I + III and IV were better preserved in 1.0 MAC and 1.5 MAC desflurane groups than in the 1.5 MAC halothane group by 34.6% (P = 0.027), 38.7% (P = 0.011), 53.9% (P = 0.009), and 55.8% (P = 0.007), respectively. Desflurane shows better preservation of mitochondrial function at 4 h after cerebral ischemia reperfusion injury, indicated by inhibition of mitochondrial swelling, increase of membrane potential, and improvement of functions of mitochondria respiratory complexes I + III and IV when compared with halothane.