Acute and Subacute Effects of Injury on the Canine Alveolar Septum: Results (6)

Acute and Subacute Effects of Injury on the Canine Alveolar Septum: Results (6)This notion gains credibility from the work of Sage et al confirmed by Lwebuga-Mukasa et al, which showed that type 2 cells in culture produce all of the major protein constituents of the alveolar basement membrane, which is a component of the alveolar septal interstitial matrix. More recently, Crouch et al demonstrated the synthesis of three collagenous macromolecules by cultured type 2 cells. These studies indicate to us a potential for type 2 cells to participate in repair processes other than merely in the replacement of type 1 epithelium. buy levaquin online
The influx of neutrophils across the alveolar septum observed in both the 4-h saline control lung and the 4-h papain-treated lung probably was due to the instillation of sterile saline solution containing the marker carbon particles (India ink). Such a response to saline alone and to carbon particles has been described by several other observers.’ The precise role of neutrophils in producing emphysema is unclear. Human neutrophil elastase is known to produce emphysema in the canine model, as shown by Janoff et al. However, Hoidal et al have shown that neutrophils per se do not appear to be essential mediators of experimentally induced emphysema in the hamster. In addition, according to Ludwig et al, the degree of emphysema in the lungs of smokers does not appear to be related to the accumulation of neutrophils in the alveolar walls. In our own experience, the instillation of 20 ml of saline solution containing 1 ml of India ink as a marker did not produce emphysema by light microscopy in three additional animals (not serially sectioned) which were sacrificed one, two and four weeks following treatment.