METABOLIC STUDIES ON THE GAS GLAND OF THE SWIM BLADDER

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Abstract
1. Metabolic studies have been carried out on the gas gland of the swim bladder of the scup, Stenotomus chrysops, at 30° C. 2. The intact gland has a Qo2 = 2.0 which is not appreciably altered by the addition of glucose. Homogenates of the gland have a much lower rate of oxygen consumption. 3. The intact gland converts glucose to lactic acid at a rapid rate. This conversion has been followed by measurement of glucose disappearance, lactic acid appearance and the release of CO2 from a bicarbonate medium. Values of QCO2NN2 ranging from 12-23 have been found. Lactic acid appearance accounts for 70-90% of the glucose that disappears. The gland does not show a Pasteur effect since similar values are obtained under either aerobic or anaerobic conditions. 4. The rate of anaerobic glycolysis is greatest at an alkaline pH and is markedly influenced by the cation composition of the medium. Activities in an all-sodium medium are 3-4 times those in an all-potassium medium. 5. A schematic diagram of the possible role of lactic acid production in the events leading to the accumulation of gas in the swim bladder is presented and calculations on the rates of oxygen production to he expected under such circumstances are made.