Adrenalectomy exacerbates paw edema without interfering with desensitization induced by PAF-acether in rats.

Subcutaneous injection of PAF-acether into the rat's paw leads to a local inflammatory response (edema) followed by desensitization after repeated injections of the substance. The desensitizing effect was not modified by previous adrenalectomy, whereas the inflammatory response observed after the first injection of PAF-acether was exacerbated. This finding suggests that adrenal hormones may act as modulators of PAF-induced inflammatory reactions. Because LY 171883, an LTD4 blocker, inhibited the edema which follows the first injection of PAF-acether, we suggest that leukotrienes may play an important role in the phenomenon.