[Effect of ligustrazine on airway remodeling in asthmatic rats].

OBJECTIVE: To observe the effect and mechanism of ligustrazine on the airway remodeling. METHODS: Thirty-two SD rats were randomly divided into 4 groups: the normal group (A), the model group (B), the ligustrazine low-dose group (C, 40 mg/kg) and the ligustrazine high-dose group (D, 80 mg/kg), with 8 rats in each group. The chronic asthmatic model was established by repeated inhalation of ovalbumin. The changes of collagen and transforming growth factor-beta(1) (TGF-beta(1)) contents in the airway wall, the thickness of smooth muscle and basement membrane, inner and outer diameter were measured by the computerized image analysis system. RESULTS: The thickness of smooth muscle and basement membrane were (11.3 +/- 1.3, 11.3 +/- 1.7) microm in D group, (19.7 +/- 1.8, 19.8 +/- 1.6) microm in B group, the difference being significant (P < 0.01), as compared with A group [(10.6 +/- 1.2) microm, (9.8 +/- 1.6) microm] and C group [(11.6 +/- 0.9) microm, (12.3 +/- 1.8) microm], the difference being not significant (all P > 0.05). The difference in the ratio of inner diameter to outer diameter was significant between D group (0.77 +/- 0.06) and B group (0.63 +/- 0.05), P < 0.01. The contents of collagen type III and TGF-beta(1) were (21 +/- 5, 26 +/- 5) in D group, (55 +/- 7, 69 +/- 14) in B group, the difference being significant (P < 0.01). The differences were also significant when C group [32 +/- 8, 38 +/- 10] was compared with D group (P < 0.05) and B group (P < 0.01). The contents of collagen type I showed no difference among the 4 groups (A group: 34 +/- 13, B group: 44 +/- 8, C group: 36 +/- 8, D group: 39 +/- 8; all P > 0.05). A close correlation between TGF-beta(1) and collagen type III was demonstrated (r = 0.844 2, P < 0.01). CONCLUSION: Ligustrazine might suppress airway remodeling by decreasing the expression of TGF-beta(1) and reducing deposition of collagen.