Reactivity of Urinary Bladder
Smooth Muscle in Guinea Pigs to Acetylcholine and Carbachol:
Participation of Acetylcholinesterase
J. MOKRÝ, M. JAKUBESOVÁ, J. ŠVIHRA1,
J. URDZIK, M. HUDEC,
G. NOSÁĽOVÁ, J. KLIMENT1
Department of Pharmacology and 1Department of
Urology, Jessenius Faculty of Medicine, Comenius University,
Martin, Slovak Republic
Received May 7, 2004
Accepted September 30, 2004
On-line available December 9, 2004
Summary
The authors examined the influence of acetylcholinesterase
inhibitor (neostigmine) on the in vitro reactivity of urinary
bladder smooth muscle (UBSM) in guinea pigs. The aim of the
present study was to determine the participation of
pharmacokinetic properties of acetylcholine and carbachol in
different UBSM reactivity to these mediators. In vitro method of
organ baths was used and reactivity of UBSM strips to cumulative
doses of acetylcholine and carbachol was tested before and after
the incubation with neostigmine (10-4 mol.l-1). Neostigmine
caused a significant increase of UBSM reactivity to
acetylcholine. The UBSM reactivity to acetylcholine was
significantly higher at concentrations of 10-5 and 10-4 mol.l-1
compared to carbachol at the same concentrations. These findings
indicate that in addition to different mediator affinity to
muscarinic receptors and to their different intrinsic activity,
the pharmacokinetic properties of acetylcholine and carbachol
also participate in UBSM reactivity.
Key words
Urinary bladder • Smooth muscle • Neostigmine • Acetylcholine •
Carbachol.
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