title: [Effect of rhythmic pressure waves on balancing airway basic mucus secretion in dogs].
abstract: OBJECTIVE
  To investigate the effect of different pressure on mucin (MUC) secretion in dog airway mucus layer and explore the participation mechanisms.
  
  
  METHODS
  Totally 24 healthy dogs were randomly divided into 4 groups (n=6) after double-lumen endobronchial tube intubation. In group A the dogs were ventilated bilaterally with normal breathing frequency and pressure; In group B: one side of the dog lung did not ventilate, while the other side was excessively ventilated. In group C: the tension-sensitive cation channel (TRPV) 4 blocker Ruthenium Red (RR) was injected in advance, and ventilated as in group A. In group D: TRPV4 blocker RR was injected firstly, and then ventilated as in group B. After 12 h ventilation, we collected bronchoalveolar lavage fluid (BALF), tested MUC (2, 5AC, 5B) protein content by ELISA, and detected the transcription of MUC (2, 5AC, 5B) mRNA of bronchial lung tissue by RTPCR.
  
  
  RESULTS
  Compared with the normal ventilation (A2) group, the protein level of MUC of excessive ventilation (B2) group was significantly higher, mainly MUC5AC (P<0.05); compared with the normal ventilation (A1) group, the protein level of MUC of no ventilation (B1) group was significantly decreased (P<0.05). After pretreatment with RR, the MUC protein level of group C1, C2 were significantly lower than that of group A1, A2 (P<0.05); the MUC protein level of group B2were significantly lower than that of group D2 (P<0.05). The MUC (2, 5AC and 5B) mRNA level was higher in excessive ventilation group (B2) than in normal ventilation group (A2). After pretreatment with RR, in comparison with group A1, A2, the MUC (2, 5AC and 5B) mRNA level of group C1, C2 declined; in comparison with group B2, the MUC (2, 5AC and 5B) mRNA level of group D2 declined.
  
  
  CONCLUSIONS
  Rhythmic pressure waves may regulate and balance basic airway mucin secretion through activating the TRPV4 channel in dogs.
authors.affiliation: Department of Respiratory Medicine, the Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China.
authors.forename: Shilan
authors.initials: S
authors.lastname: Liu
authors.forename: Juliy M
authors.initials: JM
authors.lastname: Perelman
authors.forename: Victor P
authors.initials: VP
authors.lastname: Kolosov
authors.forename: Xiangdong
authors.initials: X
authors.lastname: Zhou
mesh_terms: D000403:Airway Resistance / Q000502:physiology*; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid; D004285:Dogs; D005260:Female; D008297:Male; D009077:Mucins / Q000032:analysis; D009093:Mucus / Q000378:metabolism*; D011312:Pressure; D012123:Pulmonary Ventilation / Q000502:physiology; D020545:Respiratory Mucosa / Q000378:metabolism*; D013314:Stress, Mechanical
chemical_list: D009077:Mucins