Potentiation of acetylcholine-induced smooth muscle contraction in rat ileum by lead.
The aim of this study was to find out lead interaction on acetylcholine-induced ileal (0.8 "to 1" longitudinal total strips) contractions in varying calcium (Ca++) or magnesium (Mg++) media and the cholinergic mechanism. Potentiation of ileal strips by lead (Pb++) remained dose-dependent as elicited by acetylcholine-induced contractions (1.81 x 10(-6) M to 1.28 x 10(-4) M). These were completely antagonized by atropine (1.01 x 10(-8) M). Lead (1.2 x 10(-5) M) potentiated contractions caused by acetylcholine in normal or in excess Ca++ media, but in low Ca++ or with various Mg++ media, lead failed to potentiate such contractions. Thus Pb++ has indirect cholinomimetic effect which involved extracellular Ca++.
Gandhi
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Department of Neurobehavioural Toxicology, National Institute of Occupational Health, Gujarat, India.
Venkatakrishna-Bhatt
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D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D005260:Female; D007082:Ileum / Q000187:drug effects / Q000502:physiology; D066298:In Vitro Techniques; D007854:Lead / Q000494:pharmacology*; D008274:Magnesium / Q000494:pharmacology; D008297:Male; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar
D018727:Muscarinic Antagonists; D007854:Lead; D001285:Atropine; D008274:Magnesium; D000109:Acetylcholine