Effects of local anesthetics on the contractility of rat bladders.
OBJECTIVE
We investigated the effect of local anesthetic agents on the detrusor muscle in rats.


METHODS
In vitro isometric contraction of rat detrusor strips was measured. We investigated the effects of tetracaine, bupivacaine and lidocaine on baseline spontaneous contractions and contractions induced by various stimuli, including 60 mM. KCl, carbachol and electricalal field stimulation with a pulse duration of 0.8 or 100 milliseconds.


RESULTS
Local anesthetic agents have complex effects on baseline spontaneous contractility that depend on the type of agent used and its concentration. These agents inhibited nerve mediated contraction resulting from electricalal field stimulation with a pulse duration of 0.8 milliseconds in a concentration dependent manner and also inhibited nonnerve mediated detrusor contractions induced by KCl, carbachol or electricalal field stimulation with a pulse duration of 100 milliseconds Higher concentrations of local anesthetic agents were needed to inhibit nonnerve than nerve mediated contractions. In rat detrusor muscle carbachol induced a sustained tonic contraction even after the depletion of internal and external Ca2+ sources, which was also inhibited by local anesthetic agents.


CONCLUSIONS
These results show that local anesthetic agents have a wide spectrum of inhibitory effects on the contraction of bladder smooth muscle induced by various stimulants at different concentrations, which may be potentially useful for treating overactive bladder.
Oh
S J
SJ
Department of Urology, Seoul National University College of Medicine, Clinical Research Institute, Seoul National University Hospital, Seoul, Korea.
Kim
S J
SJ
Park
E C
EC
Chung
H K
HK
Kim
K W
KW
Choi
H
H
D000779:Anesthetics, Local / Q000494:pharmacology*; D000818:Animals; D002045:Bupivacaine / Q000494:pharmacology; D002217:Carbachol / Q000494:pharmacology; D018679:Cholinergic Agonists / Q000494:pharmacology; D005260:Female; D008012:Lidocaine / Q000494:pharmacology; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013748:Tetracaine / Q000494:pharmacology; D001743:Urinary Bladder / Q000187:drug effects / Q000502:physiology
D000779:Anesthetics, Local; D018679:Cholinergic Agonists; D013748:Tetracaine; D002217:Carbachol; D008012:Lidocaine; D002045:Bupivacaine