Role of growth factors in acute lung injury induced by paraquat in a rat model.
Paraquat (PQ) can cause acute lung injury in humans and experimental animals. However, the role of growth factors in the progression of injury has not been clearly established. We developed an animal model of PQ-induced lung injury using Wistar rats. One milliliter of PQ solution (30, 60, and 120 mg/kg) was applied through the lavage, while the same amount of vehicle was applied to control rats. Based on histopathology, the lungs of some animals exposed to PQ showed acute fulmination, resulting in death, while others showed a more protracted injury, resulting in typical pulmonary fibrosis at 21 days. Using this PQ-poisoned rat model, we examined the intrapulmonary gene expression and circulatory level of cytokines and growth factors at 8 hours, 24 hours, 3 days, 7 days, 14 days, and 21 days after PQ administration. Semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis demonstrated that the gene expression levels of interleukin-1 beta and interleukin-6 were significantly increased at 21 days after PQ challenge compared with the controls. The mRNA expression of tumor necrosis factor-alpha was also significantly increased except on days 14 and 21 after PQ treatment. Moreover, PQ-treated rats showed enhanced gene expression of growth factors such as platelet-derived growth factor-A and insulin-like growth factor-1 at 21 days and transforming growth factor-beta 1 at 14 days. ELISA results showed the circulatory level of cytokines and growth factors coincided with intrapulmonary gene expression. The synergistic effects of these molecules are presumed to cause pulmonary damage due to PQ challenge and may become targets of treatment.
Xiangdong Jian
Department of Occupational Disease and Rheumatology, Qilu Hospital affiliated to Shandong University, Jinan, P.R. CHINA. wmx1104@163.com
Ming Li
Yijing Zhang
Yanjun Ruan
Guangran Guo
Hong Sui
Yuanchao Zhang
D055371:Acute Lung Injury; D000818:Animals; D016207:Cytokines / Q000502:physiology; D004195:Disease Models, Animal; D015870:Gene Expression / Q000187:drug effects; D006540:Herbicides / Q000633:toxicity*; D007334:Insulin-Like Growth Factor I / Q000502:physiology; D036341:Intercellular Signaling Peptides and Proteins / Q000502:physiology*; D008168:Lung / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D010269:Paraquat / Q000633:toxicity*; D010982:Platelet-Derived Growth Factor / Q000502:physiology; D011654:Pulmonary Edema / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D053773:Transforming Growth Factor beta1 / Q000502:physiology
D016207:Cytokines; D006540:Herbicides; D036341:Intercellular Signaling Peptides and Proteins; D010982:Platelet-Derived Growth Factor; D053773:Transforming Growth Factor beta1; C548904:insulin-like growth factor-1, rat; C075278:platelet-derived growth factor A; D007334:Insulin-Like Growth Factor I; D010269:Paraquat