Lead acetate induced contraction in rat tracheal smooth muscle is independent of epithelium.
Airways are the primary target of lead exposure from atmospheric pollution, its effect on airway smooth muscle and their responsiveness to bronchoactive agents is not clearly understood. In the present investigation the effect of lead on the isolated airway smooth muscle activity was studied in organ bath set-up. Further the involvement of airway epithelium was examined and the responsiveness of airway smooth muscle to adenosine, acetylcholine (bronchoconstrictors) and isoproterenol (bronchodilator) was also investigated. Lead in concentration of 10(-12) M to 10(-4) M produced concentration-dependant contractile response in rat tracheal rings. Acetylcholine and adenosine induced concentration-dependent contractile response was slightly inhibited after lead exposure. The relaxant response to isoproterenol was also inhibited in lead exposed tissues. Epithelium removal did not significantly change the contractile response to lead suggesting that the lead induced contraction of airway smooth muscle is epithelium independent.
Gupta
Navin
N
Department of Physiology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi.
Fahim
Mohammad
M
D000109:Acetylcholine / Q000494:pharmacology; D000241:Adenosine / Q000494:pharmacology; D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000818:Animals; D001993:Bronchodilator Agents / Q000494:pharmacology; D018678:Cholinergic Agents / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004848:Epithelium / Q000187:drug effects* / Q000502:physiology; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009126:Muscle Relaxation / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects* / Q000502:physiology; D009942:Organometallic Compounds / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013566:Sympathomimetics / Q000494:pharmacology; D014132:Trachea / Q000187:drug effects* / Q000502:physiology; D014665:Vasodilator Agents / Q000494:pharmacology
D000318:Adrenergic beta-Agonists; D001993:Bronchodilator Agents; D018678:Cholinergic Agents; D009942:Organometallic Compounds; D013566:Sympathomimetics; D014665:Vasodilator Agents; D000241:Adenosine; D007545:Isoproterenol; D000109:Acetylcholine; C008261:lead acetate