[Pharmacological studies on supersensitization (IV). Site and mode of action of cocaine to potentiate acetylcholine in isolated tracheal preparation of rat (author's transl)]. 1978

Y Gomi, and H Komatsu

Effects of cocaine on acetylcholine-induced contracture of isolated rat tracheal preparation were determined. The sensitivity of the preparation to acetylcholine but not methacholine and carbachol was increased by cocaine. The maximum responses induced by choline esters were not augmented by cocaine. The potentiation of acetylcholine was remarkable in calcium-deficient medium and cocaine augmented acetylcholine-contracture of the preparation suspended in calcium-free Tyrode solution. Calcium-contracture of the preparation susspended in isotonic 60 mM- or 100 mM-K+ Locke-Ringer solution was not augmented by cocaine. Extrapolating the time course of decrease in acetylcholine-contracture in calcium-free Tyrode solution, rates of calcium movement from and into calcium-stores were determined and it was found that cocaine did not change the calcium-content and rate of calcium-efflux but the rate of calcium-uptake was apparently increased with cocaine. The contribution of anticholinesterase activity of cocaine to potentiation of acetylcholine appeared negligible and the affinity of acetylcholine-receptor to acetylcholine and atropine was not changed with cocaine. Thus, cocaine increases acetylcholine-induced calcium-release and potentiates acetylcholine-contracture of isolated rat tracheal preparation.

UI MeSH Term Description Entries
D008297 Male Males
D008688 Methacholine Compounds A group of compounds that are derivatives of beta-methylacetylcholine (methacholine). Compounds, Methacholine
D009119 Muscle Contraction A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments. Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
D009130 Muscle, Smooth Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed) Muscle, Involuntary,Smooth Muscle,Involuntary Muscle,Involuntary Muscles,Muscles, Involuntary,Muscles, Smooth,Smooth Muscles
D010830 Physostigmine A cholinesterase inhibitor that is rapidly absorbed through membranes. It can be applied topically to the conjunctiva. It also can cross the blood-brain barrier and is used when central nervous system effects are desired, as in the treatment of severe anticholinergic toxicity. Eserine
D002118 Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D002217 Carbachol A slowly hydrolyzed CHOLINERGIC AGONIST that acts at both MUSCARINIC RECEPTORS and NICOTINIC RECEPTORS. Carbamylcholine,Carbacholine,Carbamann,Carbamoylcholine,Carbastat,Carbocholine,Carboptic,Doryl,Isopto Carbachol,Jestryl,Miostat,Carbachol, Isopto
D003042 Cocaine An alkaloid ester extracted from the leaves of plants including coca. It is a local anesthetic and vasoconstrictor and is clinically used for that purpose, particularly in the eye, ear, nose, and throat. It also has powerful central nervous system effects similar to the amphetamines and is a drug of abuse. Cocaine, like amphetamines, acts by multiple mechanisms on brain catecholaminergic neurons; the mechanism of its reinforcing effects is thought to involve inhibition of dopamine uptake. Cocaine HCl,Cocaine Hydrochloride,HCl, Cocaine,Hydrochloride, Cocaine
D004305 Dose-Response Relationship, Drug The relationship between the dose of an administered drug and the response of the organism to the drug. Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
D004357 Drug Synergism The action of a drug in promoting or enhancing the effectiveness of another drug. Drug Potentiation,Drug Augmentation,Augmentation, Drug,Augmentations, Drug,Drug Augmentations,Drug Potentiations,Drug Synergisms,Potentiation, Drug,Potentiations, Drug,Synergism, Drug,Synergisms, Drug

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