Increased airway responsiveness after skin sensitisation to 3-carene, studied in isolated guinea pig lungs

Inhalation of 3-carene has been shown to induce bronchoconstriction in conc entrations not far from the threshold limit value. In this study, one group of guinea-pigs were sensitised by dermal exposure to 3-carene according to the modified Cumulative Contact Enhancement Test protocol and another grou p of animals was used as controls. Lungs from the skin-sensitised and contr ol guinea-pigs were perfused with diluted autologous blood (13 ml blood/87 ml buffer) and exposed to 3-carene at an air concentration of 3000 mg/m(3). In both groups there was a reduction in compliance and conductance but thi s reduction was significantly (P < 0.05) more pronounced (2.5-3 times) in l ungs obtained from sensitised animals than from control animals. In a previ ous study with similar design, but with plain buffer instead of diluted aut ologous blood as perfusate, we found no statistically significant differenc e in lung bronchoconstriction. Thus, it is concluded that skin sensitisatio n can increase lung reactivity to 3-carene and that important mediators of this effect seem to be present in the blood. (C) 2000 Elsevier Science Irel and Ltd. All rights reserved.