RESUMO
Hepatic metabolizing enzymes of diethylene glycol (DEG) are impaired in liver diseases. Thus, the purpose of this study was to increase our understandings in metabolism and toxicology of DEG by clarifying the influences of pre-existing liver disease. Forty Sprague-Dawley rats with carbon tetrachloride-induced liver cirrhosis and 20 control rats were intraperitoneally administered a single dose of DEG, and randomly killed 1, 2, 5 or 8 days following exposure. Compared with control rats, the model rats had significantly higher blood CO(2)-combining power, lower blood urine nitrogen, serum creatinine and alanine aminotransferase levels on the second day and a lower mortality rate on the eighth day following DEG exposure. Enlargements of liver and kidneys and degeneration and necrosis of hepatocytes and renal tubules in the model rats was also less serious than in the control rats. Urine DEG levels were significantly higher on the first day in the model rats than the control rats (46.65 ± 8.79 mg vs 18.88 ± 6.18 mg, p < 0.01), but DEG concentrations in the blood, liver and kidneys were lower. Hepatic alcohol dehydrogenase (ADH) activity in the model rats was significantly lower than that in the control rats, which was positively related to renal damage. The toxic effects of DEG in rats with pre-existing liver cirrhosis are significantly reduced, which may be due to the decreased hepatic ADH activity. It suggests that the metabolite of ADH is responsible for DEG poisoning, and this toxic metabolite may mainly originate in the liver.
Assuntos
Álcool Desidrogenase/metabolismo , Etilenoglicóis/toxicidade , Cirrose Hepática/enzimologia , Animais , Tetracloreto de Carbono/efeitos adversos , Modelos Animais de Doenças , Etilenoglicóis/farmacocinética , Hepatócitos/efeitos dos fármacos , Histocitoquímica , Rim/química , Rim/efeitos dos fármacos , Fígado/química , Fígado/efeitos dos fármacos , Fígado/enzimologia , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/metabolismo , Masculino , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Insuficiência Renal/induzido quimicamente , Insuficiência Renal/enzimologia , Fatores de RiscoRESUMO
A new kind of curcin (curcin 2), induced by several kinds of stresses from Jatropha curcas leaves, under the control of the 35S CaMV (cauliflower mosaic virus) promoter, was introduced into tobacco genome by Agrobacterium tumefaciens-mediated transformation method. Curcin 2 protein was only detected in the transgenic tobacco plants transformed with the cur2p fragment (coding premature curcin 2 protein), but not in the plants transformed with cur2m fragment (coding mature curcin 2 protein). The transgenic lines expressing curcin 2 showed increased tolerance to tobacco mosaic virus (TMV).
RESUMO
The open reading frame (ORF) encoding curcin 2 was cloned from total genomic and cDNA of Jatropha curcas leaves, which were treated by drought, temperature stress and fungal infection, by polymerase chain reaction (PCR) and reverse transcriptase (RT)-PCR amplification. The ORF has 927 bp that encodes a precursor protein of 309 amino acid residues. There are high similarities with curcin and the conserved domain of ribosome inactivating proteins (RIPs). Antiserum to curcin recognized one band of 32 kDa on Western blot of the leaves treated by temperature stresses at 4 degree C and 50 degree C and by fungal infections of Pestalotia funerea, Curvularia lunata (Walk) Boed, Gibberelle zeae (Schw.) Petch. Two bands of 32 kDa and 65 kDa were recognized on Western blot of the leaves treated by 10--40 percent polyethylene glycol (PEG). In addition, the 32 kDa band is nearly the molecular weight of curcin 2. This finding suggests that the protein of 32 kDa should be related to curcin 2. The presence of this protein molecular marker under stresses may provide an experimental foundation to study the stress proteins in J. curcas.
