Abstract: BACKGROUND: Hypoxic pulmonary hypertension is a key link in the progression from chronic obstructive pulmonary disease to cor pulmonale. Its severity is closely related to disease development and prognosis. Current treatments cannot prevent or reverse disease progression. Maxing Xiongting Mixture has significant effect on hypoxic pulmonary hypertension with the syndrome of intermingled phlegm and blood stasis.
OBJECTIVE: To study how the Maxing Xiongting Mixture regulates relevant factors of lung reshaping and vascular remodeling of hypoxic pulmonary hypertension rats with the syndrome of intermingled phlegm and blood stasis. 
METHODS: Seventy Sprague-Dawley rats, 5 weeks old, were randomly divided into normal group (n=10) and model group (n=60), where acute cor pulmonale model was prepared by injecting 50 mg/kg monocrotaline solution (1%) intraperitoneally, followed by forced smoking and swimming 6 days a week lasting for 4 weeks. Except for 10 rats in the normal group, there were 46 model rats in the model group. According to the normal distribution of body mass, 40 rats were selected and randomly divided into 4 groups: model group, high-dose Maxing Xiongting Mixture group (MH), low-dose Maxing Xiongting Mixture group (ML) and fasudil group, with 10 rats in each group. Rats in MH and ML groups were respectively given Maxing Xiongting Mixture at 20 g/(kg·d) and 5 g/(kg·d), respectively and those in the fasudil group were given fasudil at a dose of 10 mg/(kg·d). Other groups were given equal amount of saline. Administration was given intraperitoneally and intragastrically, once a day for 14 days in total. RT-PCR was used to test the expression of factors related to lung reshaping and vascular remodeling, including RhoA, stromelysin 1 and tumor necrosis factor-α mRNAs. An approval for the study was obtained from the Ethics Committee of Chengdu University of Traditional Chinese Medicine (approval No. 2017-03).
RESULTS AND CONCLUSION: Compared with the model group, the expressions of RhoA, stromelysin 1, and tumor necrosis factor-α mRNAs were significantly lowered in the MH group (all P < 0.05); the mRNA expressions of RhoA (P < 0.05), stromelysin 1 (P < 0.01) and tumor necrosis factor-α (P < 0.05) were significantly reduced in the fasudil group; and no significant changes in the above expressions of relevant factors were found in the ML group (P > 0.05). To conclude, Maxing Xiongting Mixture, which is similar to fasudil, intervenes lung reshaping and vascular remodeling of hypoxic pulmonary hypertension rats with the syndrome of intermingled phlegm and blood stasis by inhibiting the expressions of RhoA, stromelysin 1, and tumor necrosis factor-α mRNAs. 

Key words: Maxing Xiongting Mixture, hypoxic pulmonary hypertension, RhoA, tumor necrosis factor-α,  , stromelysin 1, lung reshaping, vascular remodeling