Experimental bronchoalveolar lavage in guinea pigs--a useful tool to investigate the intrabronchial release of substance P.

: Bronchoalveolar lavage was performed in guinea pigs during bronchial challenge with capsaicin (100 micrograms/kg b.w. intravenously) and in control animals. Capsaicin caused a bronchoconstriction (VT minimal: 27.17% +/- 24.49). There was a significant amount of substance P-like immunoreactivity, detected by RIA in the lavage fluid of four of five animals challenged with capsaicin, but only in one of five controls. These results indicate that SPLIR is released into the bronchial lumen during capsaicin-induced bronchoconstriction. So bronchoalveolar lavage may be a useful tool to investigate the role of substance P in the bronchoconstrictor response induced by various stimulants.