OBJECTIVETo investigate the effects of different concentrations of paraquat (PQ) poisoning on the expression of voltage-dependent anion channel (VDAC) and caspase family in the mitochondria of rat lung tissue, and to explore possible mechanisms of acute lung injury induced by acute PQ poisoning.

METHODSTwo hundred healthy adult Wister rats with equal numbers of male and female ones were randomly and equally divided into control group and poisoned group. The control group received one-time gastric lavage with 1 ml of normal saline, and the poisoned group with PQ (50 mg/kg) diluted in 1 ml of normal saline. Twenty rats were collected at 1, 24, 72, 120, and 168 h after lavage with normal saline or PQ and dissected after anesthesia. Mitochondria were separated from rat lung tissue, and the content of VDAC and caspase-3, -8, and -9 were determined.

RESULTSThe expression of VDAC and caspase-3, -8, and -9 in the poisoned rats were significantly higher than that in the control group (P < 0.001). At 1, 24, 72, 120, and 168 h after exposure, acute diffuse damages were found in alveolar capillary endothelial cells, alveolar epithelial cells, and pulmonary interstitial cells. Inflammatory cell infiltration in the pulmonary interstitium, alveolar structural disorder, and substantially increased fibroblasts were also found in rat lung tissue.

CONCLUSIONPQ poisoning can up-regulate the expression of VDAC and caspase-3, -8, and -9 in mitochondria of rat lung tissue to induce acute lung injury.