Mitochondria of the pulmonary granular pneumocyte in different species.

We used stereologic methods to determine the surface density and surface-to-volume ratio of mitochondrial inner membranes and cristae in pulmonary granular pneumocytes of the mouse, rat, rabbit, and dog. We also measured mitochondrial length and width and calculated their volume. The surface density of the cristae and inner membrane and the mitochondrial volume have a direct linear correlation with the oxygen consumption of lung slices of the different species. We found an indirect linear correlation between the surface-to-volume ratio of the mitochondrial inner membrane and cristae and the lung's oxygen consumption in the different species.