Correlation between lung structure and respiratory function in hamsters with experimental emphysema.

The correlation between lung structure and respiratory function was studied in normal hamsters and hamsters with elastase-induced emphysema. Four physiological parameters related to the elasticity of the respiratory system were determined from the quasi-static deflation pressure-volume curve: the shape constant (K) of the mono-exponential model fitted to the curve, the inflated volume (VI) taken as the volume change from a tracheal pressure of 0 to 30 cmH2O, the total respiratory compliance (C), determined near the relaxation volume and the normalized compliance (C/VI). The lung structure was morphologically described by the mean alveolar linear intercept (Lm) and the internal surface area (ISA). The correlations between these indices showed that 1) the four physiological parameters correlate better with Lm than with ISA, and 2) a simple index such as the normalized compliance allows to predict the severity of emphysema satisfactorily (r = 0.85; p less than 10(-6)).