Low concentrations of nonsteroidal anti-inflammatory drugs affect cell functions.

The effect of 10(-14)-10(-4)M ibuprofen and aspirin both on arachidonic acid metabolism in peritoneal murine macrophages and on the concanavalin A-induced proliferation of murine splenocytes were investigated. It was shown that 10(-7)-10(-4)M ibuprofen inhibits the arachidonic acid metabolism. On the other hand, 10(-12)-10(-11)M ibuprofen causes pronounced activation of arachidonic acid metabolism. The low concentration (10(-14)-10(-10)M) effects also take place when non-steroidal anti-inflammatory drugs influence other functions of the immune system: that is, they activate the splenocyte mitogen-induced proliferative response. These results are in accord with our suggestion that the low concentration effects of these drugs do not depend upon cell types and may have an important physiological significance.