Internal surface area and number of respiratory air spaces in elastase-induced emphysema in hamsters.

A stereologic study of the characteristics of the respiratory air spaces was carried out in 16 hamsters with emphysema induced by 0.2 mg of porcine pancreatic elastase per 100 g of body weight given endotracheally; 8 untreated hamsters served as control animals. The total number of alveoli was decreased from a mean ± SE of 5.10 ± 0.31 × 106 in the normal animals to 2.18 ± 0.27 × 106 in the emphysematous animals. The average ± SE mean linear intercept was 55 ± 1 × 10−4 cm for the normal group and 105 ± 4 × 10−4 cm for the emphysematous group. The mean ± SE internal surface area calculated from the mean linear intercept was 3,830 ± 125 cm2 for the normal group and 2,794 ± 85 cm2 for the emphysematous group; the comparable values calculated by the air space density method were 6,221 ± 183 and 4,281 ± 127 cm2, respectively. The mean internal surface area of the emphysematous lungs was 73 per cent of normal by the mean linear intercept method and 67 per cent of normal by the air space density method; the inter...