The Carbohydrate Metabolism and Respiration of Isolated Small Lymphocytes : In Vitro Studies of Normal and Phytohemagglutinin Stimulated Cells

1. A homogeneous population of small lymphocytes with an average size of 6.7 micra was isolated from equine blood.

2. These cells could be maintained in vitro, with essentially complete survival for 24 hours, and with a 50% viability for five days.

3. The small lymphocytes consumed glucose at a rate of 1.87 mµmoles/1 x 10⁷ cells/minute, and produced lactic acid at a rate of 2.30 mµmoles/1 x 10⁷ cells/minute.

4. The oxygen consumption of small equine lymphocytes was 1.023 ± .165 mµmo1es oxygen 1 x 10⁷ cells/minute, and that of mixed peripheral blood leukocytes, 1.25 ± .07 mµmoles oxygen/1 x 10⁷ cells/minute, as determined, using a Clark oxygen electrode.

5. Lymphocyte glycolysis was stimulated under anaerobic conditions (Pasteur effect), and viability appeared unimpaired after 24 hours in a N₂ environment.

6. Uncoupling of oxidative phosphorylation by the addition of 2,4, dinitrophenol stimulated both respiration and glycolysis.

7. The glycogen content of the normal small horse lymphocyte was 7.45 ± 1.04 µg glucose equivalents per 1 x 10⁷ cells.

8. Many of the initial cell population were transformed into "blasts" following the addition of phytohemagglutin to the tissue culture medium. This response was associated with an increase in the rate of glycolysis and respiration by 24 hours, and a rise in intracellular glycogen by 48 hours.