Chapter 9. Peripheral Actions of Selective Muscarinic Agonists and Antagonists

Author(s):  
G. Mihm ◽  
B. Wetzel ◽  
Dr. Karl Thomae Gmbh
2001 ◽  
Vol 44 (26) ◽  
pp. 4563-4576 ◽  
Author(s):  
W. G. Rajeswaran ◽  
Yang Cao ◽  
Xi-Ping Huang ◽  
Mary Elizabeth Wroblewski ◽  
Tracy Colclough ◽  
...  

1992 ◽  
Vol 2 (8) ◽  
pp. 791-796 ◽  
Author(s):  
Steven M. Bromidge ◽  
Frank Brown ◽  
Frederick Cassidy ◽  
Michael S.G. Clark ◽  
Steven Dabbs ◽  
...  
Keyword(s):  

Open Medicine ◽  
2009 ◽  
Vol 4 (2) ◽  
pp. 192-197 ◽  
Author(s):  
A. Canda ◽  
Christopher Chapple ◽  
Russ Chess-Williams

AbstractThe aim of the study was to determine pathways involved in contraction and relaxation of the mouse urinary bladder. Mouse bladder strips were set up in gassed Krebs-bicarbonate solution and responses to various drugs and electrical field stimulation were obtained. Isoprenaline (b-receptor agonist) caused a 63% inhibition of carbachol precontracted detrusor (EC50=2nM). Carbachol caused contraction (EC50=0.3µM), responses were antagonised more potently by 4-DAMP (M3-antagonist) than methoctramine (M2-antagonist). Electrical field stimulation caused contraction, which was inhibited by atropine (60%) and less by guanethidine and α,β-methylene-ATP. The neurogenic responses were not potentiated by inhibition of nitric oxide synthase. Presence of an intact urothelium significantly depressed responses to carbachol (p=0.02) and addition of indomethacin and L-NNA to remove prostaglandin and nitric oxide production respectively did not prevent the inhibitory effect of the urothelium. In conclusion, b-receptor agonists cause relaxation and muscarinic agonists cause contraction via the M3-receptor. Acetylcholine is the main neurotransmitter causing contraction while nitric oxide has a minor role. The mouse and human urothelium are similar in releasing a factor that inhibits contraction of the detrusor muscle which is unidentified but is not nitric oxide or a prostaglandin. Therefore, the mouse may be used as a model to study the lower urinary tract.


1978 ◽  
Vol 56 (6) ◽  
pp. 921-925
Author(s):  
L. Spero

A technique is described which has enabled us to measure changes in 22Na+ efflux from smooth muscle plasma membrane vesicles. The resting 22Na+ efflux from these sealed vesicles showed a concentration-dependent increase in response to acetylcholine and other muscarinic agonists, in similar concentrations to those which increased 42K+ efflux in whole muscle. The kinetics of this efflux were complex and could not be described by less than three exponential processes. The response to agonists has, therefore, been characterized by measurement of the half-life of 22Na+ efflux (t1/2). The acetylcholine effect was inhibited by atropine, but unlike the situation in the whole muscle, this inhibition was noncompetitive. Tubocuraine (a nicotinic antagonist) had no effect on this acetylcholine response. Atropine has no effect by itself on the resting 22Na+ efflux, neither did tetrodotoxin or ouabain. 22Na+ efflux from erythrocyte ghosts and liposomes, prepared from lipid extracts of the smooth muscle plasma membrane, was not modified by acetylcholine or atropine.


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