In vitro effect of toluene diisocyanate on beta adrenergic and muscarinic receptor function in lung tissue of the rat.

To investigate the role of pharmacological mechanisms in toluene diisocyanate (TDI) induced occupational asthma, the effects of TDI on rat trachea ring and lung parenchymal strip were studied in vitro. The most prominent effect observed was a stimulation of metacholine (1 microM) induced contraction of the tracheal ring by 1 microM TDI (added in dimethy sulphoxide). The results were less pronounced when TDI was added from a stock solution prepared in water, which is possibly due to (co)polymerisation. It is concluded that the pharmacological effect of TDI may result from an autonomic imbalance between cholinergic and beta-adrenergic neural control.