Pulmonary inactivation of 5-hydroxytryptamine is decreased during cigarette smoke ventilation of rat isolated lungs.
1 The effect of cigarette smoke ventilation on the inactivation of [14C]-5-hydroxytryptamine (5-HT) was studied in isolated perfused lungs of the rat. 2 [14C]-5-HT 9.6 nmol was infused into the pulmonary circulation of rat lungs in 3 min. The nonrecirculating perfusion effluent was collected during the 5-HT infusion in three consecutive 1 min fractions. The amount of metabolites of 5-HT was determined from the perfusion effluent and from the perfused lungs. 3 The amount of metabolites of 5-HT in the perfused lungs was also decreased by cigarette smoke ventilation, although the total amount of radioactivity in the lung tissue was not significantly changed. 5 The decreased pulmonary inactivation of 5-HT may cause increased circulating levels of 5-HT, which would explain some cardiovascular changes during smoking.
D000818:Animals; D001711:Biotransformation; D066298:In Vitro Techniques; D008168:Lung / Q000378:metabolism*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism*; D012907:Smoking
D012701:Serotonin