Influence of UV- and capsaicin-induced erythema as well as of acetylsalicylic acid on the urinary excretion of vanilmandelic acid and homovanillic acid in man.

In the present study we investigated whether by means of urinary excretion of vanilmandelic acid (VNA) and homovanillic acid (HVA), resp., the two main metabolites of adrenaline, noradrenaline and dopamine, informations could be obtained on synthesis and release of catecholamines in inflammation. UV- and capsaicin-induced erythema, resp., were used as the inflammatory models. The urinary excretion or both VMA and HVA were found to be decreased after UV irradiation. Administration of acetylsalicylic acid during UV irradiation inhibited the decrease of VMA excretion whereas HVA excretion remained low. The application of capsaicin as a plaster failed to influence the urinary VMA and HVA excretion. Our results could be explained on the basis of the interrelationship between catecholamines and prostaglandins. Other possible mechanisms are discussed.