Evidence that genetic emphysema in tight-skin mice is not caused by neutrophil elastase

Mutant tight-skin mice that had severe pulmonary emphysema were crossed with beige mice that contained neutrophils deficient in elastase activity. The resultant tight skin-beige cross mice were deficient in neutrophil elastase activity, yet they were still afflicted with the same degree of severe emphysema as the tight-skin mice. The results indicate that neutrophil elastase does not cause the emphysematous lesions found in tight-skin mice.