DETERMINATION OF BRADYKININ-(1-5) IN INFLAMMATORY EXUDATE BY A NEW ELISA AS A RELIABLE INDICATOR OF BRADYKININ GENERATION

We have developed an ELISA for BK-(1-5) (Arg(1)-Pro(2)-Pro(3)-Gly(4)-P he(5)). In rat carrageenin-induced pleurisy, in which a plasma exudati on peak was observed 5 h after carrageenin, BK levels in the exudates were negligible (< 60 pg/rat). BK-(1-7) (des-Phe(8)-Arg(9)-BK) was det ectable (900-400 pg/rat) over the entire course of the inflammation. H owever, a larger amount of BK-(1-5) was detectable in association with the increase in plasma exudation, showing a peak (8800 +/- 1200 pg/ra t) 3 h after carrageenin. Bromelain (10 mg/kg, i.v.) and soy bean tryp sin inhibitor (0.3 mg/rat, intra-pleural) significantly reduced BK-(1- 5) levels (by 60-93%, 3, 7 and 19 h after carrageenin) and plasma exud ation rates (by 61-74%, 3 and 7 h after carrageenin). Dexamethasone (0 .3 mg/kg, i.p.) reduced BK-(1-5) levels (by 78%) and decreased plasma exudation (by 70%) 3 h after carrageenin, In nasal allergy patients, a ntigen challenge of nasal mucosa elevated BK-(1-5) revels and active k allikrein levels in nasal washes. These results verify that BK-(1-5) d etermined by ELISA is a good indicator for release of kinins in vivo.