Abstract: AIM: To observe the effect of ligustrazine on the calcium contents and calmodulin activity of lung tissue in rats of the bleomycin-induced pulmonary fibro-sis.METHODS: Thirty-two SD rats were replicated into pulmonary fibrosis models by intratracheal injection of bleomycin A 5 in one lump and were divided into two groups randomly, untreated model group (n=16) and ligustrazine group(n=16).The calcium contents and calmodulin activity of the lung of the rats of each group were assayed on d 14, d 28 after the injection and com-pared with control group (n=8).RESULTS: The cal-cium contents and calmodulin activity of model group were obviously higher than control group (P<0.01), and ligustrazine groupwere lower than those of model group at all pases (P<0.05).The degree of alveolitis and fibro-sis of the lung studied by histopathology was lower than that in the model group.CONCLUSION: The mecha-nism of the protective effect of ligustrazine on bleomycin-induced pulmonary fibrosis may be related to decrease the calcium contrents and calmodulin activity.

Key words: oigustrazine, pulmonary fibrosis, calcium contents, calmodulin activity