Does airway responsiveness increase after skin sensitisation to 3-carene: a study in isolated guinea pig lungs

Guinea pigs were sensitised by dermal exposure to 3-carene according to the modified cumulative contact enhancement test (CCET) protocol. Lungs from sensitised and non-sensitised animals were then perfused with buffer and exposed for a period of 10 min to two different air concentrations of 3-carene, 600 and 3000 mg/m3. 3-Carene caused a statistically significant bronchoconstriction even at the relatively low concentration of 600 mg/m3 and the constriction was dose dependent. 600 mg/m3 of 3-carene caused a reduction of 19% in conductance capacity and 16% in compliance capacity. 3000 mg/m3 of 3-carene decreased lung compliance and conductance by 43 and 31%, respectively. The lungs from sensitised animals tended to show a greater response than lungs obtained from control animals. The lower concentration of 3-carene is close to and may even be below, occupational limit values in Sweden, Germany and USA.