Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
Date (from‐to) : 2017/04 -2021/03
Author : Hashitani Hikaru
Contractile properties of muscularis mucosae (MM), the predominant contractile element in the bladder mucosa, was compared with those of detrusor smooth muscle (DSM). MM develops vigorous spontaneous phasic contractions arising from bursting action potential firing but modestly responds to the excitatory, cholinergic innervation, suggesting that it play its major role during storage rather than voiding phase. Unlike DSM lacking inhibitory innervation, MM receives the inhibitory nitrergic innervation. MM also exhibits a much greater sensitivity to angiotensin II (ATII) than DSM that could well sense circulating concentration of ATII, suggesting that MM is the predominant target of contractile actions of ATII in the bladder. The MM contractility appears to be diminished by as yet unidentified substance released from the urothelium. The contractile properties of MM could be a novel therapeutic target in the treatment of overactive bladder.