title: [Dose-effect relationship between vitamin C and paraquat poisoning rats].
abstract: To explore the dose-effect relationship between vitamin C and paraquat (PQ) poisoning rats.  Methods: A total of 40 Sprague-Dawley (SD) rats were randomly divided into 4 groups: a control group, a PQ poisoning group, a vitamin C group 1 and a vitamin C group 2 (n=10 in each group). 150 mg/kg PQ was perfused into rat stomach to establish PQ poisoning rat model. In PQ poisoning group, 30 mg/kg methylprednisolone and 2.5 mg/kg cyclophosphamide were injected peritoneally on the basis of PQ poisoning rat model. In vitamin C1 and C2 group, vitamin C was injected at a dosage of 5 or 500 mg/kg, respectively. The control group only received normal saline (NS). The malondialdehyde (MDA), liver and kidney function as well as arterial blood gas in the blood were examined 36 h later. At the end, the rats were killed and took the liver tissues for pathological examination and weight ratio calculation. The glutathione peroxidase (GSH-PX), ctychrome C (Cyt C) in the liver tissues were detected by chromatometry, and the Bcl-2 was detected by Western blot.  Results: Compared with the PQ poisoning group, the MDA and Cyt C were decreased, the GSH-PX was increased, and liver and kidney functions were improved in the vitamin C group 1 (all P<0.01); but in the vitamin C group 2, the MDA increased and liver/kidney functions were impaired (all P<0.01). The expression of Bcl-2 in the PQ poisoning group was lower than that in the control group; compared with the PQ poisoning group, it was increased in the vitamin C1 group, while it was decreased in the vitamin C group 2 (both P<0.01). There was no obvious difference in the lung function, wet/dry weight ratio and pathological changes between the poisoning group and experimental groups (all P>0.05).  Conclusion: Vitamin C at the low dose shows a certain degree of protection for the liver and kidney in the PQ poisoning rats model through it antioxidative activity and anit-apoptosis activity, while vitamin C at the high does may promote oxidation. Meanwhile, vitamin C doesn't show protective effect on lung in the PQ poisoning rats.
authors.affiliation: Department of Emergency, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China.
authors.forename: Baoling
authors.initials: B
authors.lastname: Wen
authors.affiliation: Department of Emergency, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Yu
authors.affiliation: Department of Emergency, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Fang
authors.affiliation: Department of Emergency, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China.
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Wang
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001205:Ascorbic Acid / Q000008:administration & dosage* / Q000494:pharmacology*; D045304:Cytochromes c / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005979:Glutathione Peroxidase / Q000187:drug effects; D007668:Kidney / Q000187:drug effects* / Q000473:pathology* / Q000503:physiopathology*; D008168:Lung / Q000187:drug effects* / Q000473:pathology* / Q000503:physiopathology*; D008315:Malondialdehyde / Q000378:metabolism; D010269:Paraquat / Q000633:toxicity*; D020011:Protective Agents / Q000494:pharmacology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D014815:Vitamins
chemical_list: D020011:Protective Agents; D019253:Proto-Oncogene Proteins c-bcl-2; D014815:Vitamins; D008315:Malondialdehyde; D045304:Cytochromes c; D005979:Glutathione Peroxidase; D010269:Paraquat; D001205:Ascorbic Acid