Changes of respiratory function on urine volume, renal AQP1, and AQP2 in mice with bronchial asthma and effects of lung-diffusing herb Platycodon grandiflorus (JACQ.) A.DC.

Objective:To observe the effect of respiratory-function changes on urinary output and expression of aquaporin (AQP) in kidney tissue in bronchial asthma (BA) model mice.To explore the correlation between the lung controlling breathing and the lung regulating the waterways,and observe regulation by the lung-diffusing herb platycodon root (Platycodon grandiflorus (JACQ.) A.DC.).Methods:Forty-five healthy female Balb/c mice were divided randomly into normal,model and platycodon root groups.The BA model was replicated by complex sensitization and stimulation with ovalbumin (OVA).Changes in airway resistance were detected using an AniRes2005 system,and 24-hour urine output collected by metabolic cages.Histopathologic changes in the lung and kidney were observed by H&rE staining.Expression of the mRNA of AQP1 and AQP2 was detected by reverse transcription-polymerase chain reaction,immunohistochemistry,and immunofluorescence.Results:Compared with the normal group,airway resistance in the inspiratory phase intensified in the model group (P <.01).Following the pathologic changes in lung tissue,but no significant change in kidney tissue,24-hour urinary output decreased significantly (P <.05),and levels of AQP1,AQP2 and their mRNA increased significantly in the model group (P <.01).Compared with the model group,airway resistance in the inspiratory phase was weakened(P <.01).The urinary output increased (P <.05),pathologic changes in lung tissues decreased,and renal expression of AQP1,AQP2 and their mRNA decreased significantly (P <.01) in the platycodon root group.Conclusion:Changes in respiratory function in BA model mice can affect how the lung regulates water pathways.Platycodon root diffusing the lung can ameliorate the respiratoryfunction and pathologic changes in the lung tissues of BA model mice,but also regulate urinary output and renal expression of AQP1 and AQP2.

Effect of mechanical ventilation on urine volume and expression of aquaporins in rabbits

Objective:To explore biological mechanisms underlying the traditional Chinese medicine theory of 'lung governing the regulation of water passage' by observing effects of mechanical ventilation on urine volume and related bioactive substances.Methods:A total of 16 male rabbits were randomly divided into control and lung expansion model groups (n =8 per group),which were examined during the following four respiratory intervention stages (10 minutes each):(1) free breathing without any respiratory intervention;(2) lung expansion induced by mechanical ventilator;(3) free breathing without ventilator intervention;(4) cutting of bilateral sympathetic,vagus,and depressor nerves with mechanical ventilation.Data for breathing rate,blood pressure,and urine drops were recorded with a Medlab data acquisition system.Levels of nitric oxide (NO),antidiuretic hormone (ADH),endothelin 1 (ET-1),angiotensin Ⅱ (AngⅡ),prostaglandin E2 (PGE2),and atrial natriuretic peptide (ANP) were detected in lung tissue,kidney tissue,and serum by enzyme-linked immunosorbent assay.Protein expression of aquaporins 1 and 2 (AQP1 and AQP2) was detected in kidney tissue by immunohistochemistry,while Aqp1 mRNA and Aqp2 mRNA levels in kidney tissue were detected by real-time quantitative polymerase chain reaction.Histopathological changes in lung and kidney tissues were examined by hematoxylin and eosin staining.Results:Compared with the control group,number of urine drops during the second and fourth stages is significantly decreased in the model group (P <.05).In addition,NO and PGE2 content in lung and kidney tissues was significantly decreased in the model group (P <.05).ANP content in model group lung and kidney tissues was significantly increased (P <.05),while ET-1 content in these tissues was significantly decreased (P <.05).AngⅡ content in kidney tissue was significantly decreased in the model group (P <.05),while serum AngⅡ content of the animals was significantly increased (P <.05).Expression of AQP1 and AQP2 proteins in kidney tissue was significantly higher in the model group than in the control group (P <.05).No obvious histopathological changes were observed in lung or kidney tissues of animals in either group.Conclusions:Mechanical ventilation reduced urine volume,increased expression of AQP1 and AQP2 in kidney tissue,and altered levels of NO,ADH,ET-1,AngⅡ,PGE2,and ANP in lung tissue,kidney tissue,and serum.These results provide an experimental basis for preliminary studies of mechanisms under pinning the theory of 'lung governing the regulation of water passage'.