A METHOD FOR THE STUDY OF THE INTERMEDIARY CARBOHYDRATE METABOLISM OF EPIDERMIS .1. OXIDATION OF ACIDS OF THE CITRIC ACID CYCLE

[摘要] A study of the intermediary pathways of carbohydrate metabolism in epidermis would be the first step in the search for the source of energy required for wound repair, keratinization and growth. A method for approaching this problem has been outlined: it involves a study of the metabolism of homo-genates of rat epidermis prepared in the Potter-Elvehjem glass homogenizer. Since respiration provides most of the energy in many tissues, this phase of carbohydrate metabolism was studied. The conditions for obtaining opt basal respiration of epidermis homogenates are as follows: 1.0 ml. homogenate in 0.154 [image] KCl, 0.3 ml. 0.125 M phosphate buffer pH 7.4, 0.1 ml. 0.1 [image]MgCl2, 02 ml. 0.02 M adenosine -5-phosphate, 0.1 ml. 10-3 M cytochrome c. and 0.154 [image] KCl to a total volume of 3.0 ml. O2 uptake was measured in Warburg respirometers with air as the gas phase at 37[degree]C after temp. equilibration of 15 min. The Q02 of homogenates under these conditions averaged 0.587 with a standard deviation of + 0.190. The addition of 50 micromoles of succinate, oxalacetate, alpha-ketoglutarate, fumarate and malate each separately to the above reaction mixture caused a significant stimulation of the basal Q02- Glutamate and citrate did not stimulate, while pyruvate was equivocal. The implications of these findings are briefly discussed.