Studies on the particulate components of rat mammary gland. 1. A method for determining the composition of the retained fluid

McARDLE 1957 in greater amount than pyruvate, and other a-keto acids are also present in small amounts.Kulonen et al. (1952) reported a mean daily excretion in five subjects of 16-9 mg. of pyruvate and 14-0 mg. of a-oxoglutarate.The level of activity of the subjects is not mentioned, but it seems likely that the high pyruvate excretion may have been the result of exercise, since it has been shown by Johnson & Edwards (1937) and by McArdle (unpublished work) that the excretion of pyruvate is greatly increased after strenuous exertion.A point of some interest that is being further investigated is the higher excretion rate of oc-oxoglutarate in women.SUMMARY 1.A simplified procedure is described for the separation of the 2:4-dinitrophenylhydrazones of a-keto acids by paper chromatography, and for the quantitative estimation ofthe separated hydrazones of pyruvate and a-oxoglutarate.2. Values are given for pyruvate and a-oxoglutarate in post-absorptive blood from healthy resting human subjects, in cerebrospinal fluid and in urine.3. The rate of excretion of oc-oxoglutarate in urine is greater in women than in men.