Collateral ventilation in excised dog lungs

¹ The First Department of Internal Medicine, Tohoku University School of Medicine, Sendai, Japan

Lobes of excised dog lungs were cannulated so that all segmental bronchi were connected to one of two cannulae. When one cannula was obstructed all ventilation beyond the point of obstruction was through collateral passages. Changes in effective lobar compliance with cycle duration, and changes in the lobar spirograms following abrupt changes in translobar pressure were interpreted in terms of underlying changes in collateral flow. In lobes from six dogs collateral flow was not detected in two and showed marked individual variations in the other four. It decreased relative to total lobar flow when the duration of the imposed volume cycle was decreased, and it increased when the degree of lobar inflation was increased. The latter finding suggested associated increases in the size of the stomata between adjoining alveoli.

Submitted on September 11, 1963