G Zhang1, Z Lin, B Zhang. 1. Department of Pharmacology, Beijing Medical University.
Abstract
OBJECTIVE: To investigate the role and induced regulation of nitric oxide (NO) in rat immunological hepatic injury, and the effect of selective inhibitor on induceble nitric oxide synthase (iNOS). METHODS: The intracellular NOS gene expression in the immune damaged hepatocytes was determined by in situ PCR technique, and NO concentration and lactate dehydrogenase (LDH) activity in culture supernatant were measured. RESULTS: Administration of bacille calmette guerin (BCG, 15, 30, 50 mg/rat, i.v.) alone or BCG with the inflammatory cytokines mixture (CM), including IL-1 beta, IFN-gamma, TNF-alpha and lipopolysacchride (LPS) significantly increased NO production and LDH release in culture medium(P < 0.05). NO production was enhanced with hepatic injury degree in direct proportion, and with BCG dose in inverse proportion. Under immunological stimuli condition, hepatocytes NOS mRNA mainly expressed an induceble and soluble isoform (iNOS) in cytoplasm. Aminoguanidine (AG), a selective iNOS inhibitor, inhibited NO production and LDH release (83.4% and 36.0%, P < 0.05), but the transcription inhibitor actinomycin D enhanced LDH level in the medium (25.5%, P < 0.05). CONCLUSION: NO produced by immunological stimuli participates in rat hepatic injury mechanism.
OBJECTIVE: To investigate the role and induced regulation of nitric oxide (NO) in ratimmunological hepatic injury, and the effect of selective inhibitor on induceble nitric oxide synthase (iNOS). METHODS: The intracellular NOS gene expression in the immune damaged hepatocytes was determined by in situ PCR technique, and NO concentration and lactate dehydrogenase (LDH) activity in culture supernatant were measured. RESULTS: Administration of bacille calmette guerin (BCG, 15, 30, 50 mg/rat, i.v.) alone or BCG with the inflammatory cytokines mixture (CM), including IL-1 beta, IFN-gamma, TNF-alpha and lipopolysacchride (LPS) significantly increased NO production and LDH release in culture medium(P < 0.05). NO production was enhanced with hepatic injury degree in direct proportion, and with BCG dose in inverse proportion. Under immunological stimuli condition, hepatocytes NOS mRNA mainly expressed an induceble and soluble isoform (iNOS) in cytoplasm. Aminoguanidine (AG), a selective iNOS inhibitor, inhibited NO production and LDH release (83.4% and 36.0%, P < 0.05), but the transcription inhibitor actinomycin D enhanced LDH level in the medium (25.5%, P < 0.05). CONCLUSION: NO produced by immunological stimuli participates in rathepatic injury mechanism.