Abstract
The effect of isomeric
cis-octadecenoic acids on growth of monkey kidney (MK
2) cells was variable.
1.
1. When 10 μ/ml of the 5-, 6-, 7-, 8-, 9-, 10-, 11-, l3-, 14-,16–l8:1 isomers were added to medium, a stimulation in growth of MK
2 cells occurred.
2.
2. Isomeric octadecenoic acids 3–18:1 or 17–18:1 (10 μg/ml) were inhibitory for MK
2 cell growth.
3.
3. Inhibition of cell growth was observed within 24 h when the medium contained 20 to 40 μg/ml of 3–18:1, and after 72 h almost all cells had lysed. A slight stimulation in growth of cells did occur with 3–18: 1 when the concentration was 5 μg/ml or less.
4.
4. The addition of as little as 2.5 μ/ml of 9–18:1 to medium containing the inhibitory level of 3–18:1 (20 μ/ml) increased the cell population to 50 % of the control population.
5.
5. When a combination of 20 μ/ml each of 9–18:1 and 3–18:1 was added to the medium an increase in cell growth was observed but not a complete reversal of the inhibition.
6.
6. Cells which had been maintained in a basal medium up to 96 h before the isomer was added responded similarly to cells which had the isomer added at 24 h.
7.
7. MK
2 cell growth was inhibited by 3–18: 1 and stimulated by 8–18: 1. This was opposite to the response observed for growth of a bacterium,
Leptospira interrogans serotype
patoc.