The in vitro respiration of normal brain and brain tumors.

The respiratory rates of normal and neoplastic cerebral tissues, and the effect of various anticancer drugs upon them, were measured according to the standard in vitro Warburg technic. The temporal and parietal lobes of normal brain had higher respiratory rates than did the occipital and frontal lobes, and gray matter had a much higher respiratory rate than white matter. Primary and metastatic brain tumors had respiratory rates similar to normal white matter, the degree of malignancy of brain tumors being inversely proportional to the respiratory rate. The respiration of normal brain tissue was usually inhibited by each anticancer drug, whereas the response of brain tumors was variable. Of particular interest was the stimulatory effect of A139 and methotrexate upon the respiration of certain tumors.