Uptake of zimelidine and inhibition of uptake of 5-hydroxytryptamine in the isolated, ventilated and perfused rat lung.

Uptake of zimelidine from the perfusate in isolated perfused rat lung was concentration-dependent. Accumulated zimelidine was released from the lung according to a two-compartment model and lidocaine injected as a bolus did partially displace zimelidine. The properties of the displacement curves indicated, however, that the affinity to the lung tissue was greater for zimelidine than lidocaine. Uptake of 5-hydroxytryptamine added to the perfusion buffer was inhibited by zimelidine. The displacement of zimelidine by lidocaine did not, statistically, significantly alter the extraction of 5-hydroxytryptamine.