title: [A guinea pig model of parainfluenza virus type 3 infection-induced acute and postinfectious cough].
abstract: OBJECTIVE
  To establish a guinea pig model of cough induced by human parainfluenza virus type 3 (PIV3) infection, and to investigate the change of the cough reflex sensitivity (CRS).
  
  
  METHODS
  Sixty male SPF guinea pigs were divided into 6 groups (n=10, each), namely, a normal control group, an asthma group and 4 groups of PIV3 inoculation which included post-infection day (PID) 6, 12, 28, and 42. Infected animals were inoculated by intranasal instillation of PIV3 suspension. Control animals were inoculated by uninfected cell culture medium. Asthma animals were sensitized and challenged by ovalbumin. The Buxco system was used to assess cough reflex sensitivity (CRS) elicited by capsaicin and airway hyper-reaction (AHR). Airway inflammation was studied by bronchoalveolar lavage (BAL) cytology and lung histopathology.
  
  
  RESULTS
  The CRS of PID 6, 12, 28 and 42 groups was 7.50 (5.25), 7.30 (7.25), 8.40 (9.75) and 8.20 (5.50) Cough counts (CCnt). Compared with 2.50 (3.00) CCnt of the vehicle group, the CRS to capsaicin increased significantly in all the animals with PIV3 inoculation (P value were 0.024, 0.03, 0.011 and 0.008) and peaked in PID 42. There was no significant difference (P=0.18) between 3.90 (1.75) CCnt of the asthma animals and the normal control. Animals of PID 6 showed significantly greater AHR to 2 highest concentrations of methacholine than the normal controls. BAL total cell counts of both the PIV3-inoculated and the asthma animals were significantly higher than those of the normal control, with the number of lymphocytes increased significantly within first 2 weeks after PIV3 inoculation. The lung pathology of PIV3-inoculated animals showed airway inflammation without pneumonia in acute infectious phase.
  
  
  CONCLUSIONS
  An animal model of cough induced by PIV3 was created. The CRS of infected guinea pigs increased significantly in both acute and subacute phases of cough. Elevation of CRS may be characteristic of cough caused by virus.
authors.affiliation: State Key Laboratory of Respiratory Disease (Guangzhou Medical College), Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical College, Guangzhou 510120, China.
authors.forename: Xin-min
authors.initials: XM
authors.lastname: Ye
authors.forename: Nan-shan
authors.initials: NS
authors.lastname: Zhong
authors.forename: Chun-li
authors.initials: CL
authors.lastname: Liu
authors.forename: Rong
authors.initials: R
authors.lastname: Liu
authors.forename: Ke-fang
authors.initials: KF
authors.lastname: Lai
authors.forename: Ru-chong
authors.initials: RC
authors.lastname: Chen
mesh_terms: D000818:Animals; D001249:Asthma / Q000821:virology; D003371:Cough / Q000821:virology*; D004195:Disease Models, Animal; D006168:Guinea Pigs; D008297:Male; D010224:Parainfluenza Virus 3, Human / Q000472:pathogenicity*; D018184:Paramyxoviridae Infections / Q000503:physiopathology*