A Microspectrophotometric Technique for Determination of Respiration in Comparison to the Cartesian Diver Method. —Respiratory Activity of Rat Corpus Luteum Cells with Reference to Substrate

A comparative study of two microrespirometric methods, the classical standard‐diver technique and a newly introduced spectrophotometric procedure, using hemoglobin as indicator of oxygen tension as well as donor of oxygen, has been performed on small samples of well‐defined rat corpus luteum tissue. Oxygen consumption of this tissue was determined in absence of substrate as well as in the presence of oxalacetate and succinate, respectively. The accuracy of the two methods was equal though small differences in absolute values were found. Rapidity and simplicity of performance is considerably increased with the spectrophotometric procedure. Endogenous respiration was found to be approximately 1 μl O2/mg dry weight × h, and in the presence of oxalacetate oxygen consumption was increased by 50 per cent. In the presence of succinate respiration was increased to about 10 μ O2/mg dry weight × h.