The tachykinin NK-2 receptor antagonist SR48968 does not block noncholinergic contractions in unstable human bladder.
Concentration-response curves to acetylcholine, and responses to electrical field stimulation (EFS) were compared in detrusor muscle strips, from control patients and those with idiopathic detrusor instability (IDI). Responses were similar in both groups. However, atropine abolished responses to EFS in 80% of control but only 33% of IDI patients (P>0.05), with the residual atropine-resistant response in most IDI patients abolished by tetrodotoxin. The post-atropine residual response was unaffected by the tachykinin NK-2 receptor antagonist SR48968. Despite the known existence of NK-2 receptors in the human detrusor, there was no evidence for tachykinin contribution to EFS-induced contractions.
The Detrusor Muscle Laboratory, Pitney Clinical Sciences Building, Pelvic Floor Unit, St. George Hospital, Kogarah, NSW 2217, Sydney, Australia. k.moore@unsw.edu.au
Kate H
KH
Moore
David S H
DS
Lam
William
W
Lynch
Elizabeth
E
Burcher
D000109:Acetylcholine / Q000378:metabolism; D000368:Aged; D001549:Benzamides / Q000494:pharmacology*; D016022:Case-Control Studies; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D005260:Female; D006801:Humans; D008875:Middle Aged; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology*; D010880:Piperidines / Q000494:pharmacology*; D011950:Receptors, Cholinergic / Q000378:metabolism; D018041:Receptors, Neurokinin-2 / Q000037:antagonists & inhibitors*; D015320:Tachykinins / Q000378:metabolism; D001743:Urinary Bladder / Q000187:drug effects* / Q000378:metabolism; D014549:Urinary Incontinence / Q000188:drug therapy* / Q000378:metabolism*
D001549:Benzamides; D010880:Piperidines; D011950:Receptors, Cholinergic; D018041:Receptors, Neurokinin-2; D015320:Tachykinins; C073839:SR 48968; D000109:Acetylcholine