Detrusor contraction

Abstract

Stimulation of muscarinic receptors is a main mechanism for contractile activation of the detrusor from both animals and humans. Muscarinic receptors are coupled to G-proteins, but the signal transduction systems may vary. In general, M[Formula: See Text], M[Formula: See Text] and M[Formula: See Text] receptors are considered to couple preferentially to G[Formula: See Text], activating phosphoinositide hydrolysis, in turn leading to mobilization of intracellular calcium through inositol trisphosphate generation. M[Formula: See Text] and M[Formula: See Text] receptors couple to pertussis toxin-sensitive G[Formula: See Text], resulting in inhibition of adenylyl cyclase activity. However, in the detrusor smooth muscle, other signalling pathways may be involved. Recent investigations revealed that a main pathway for muscarinic receptor activation of the detrusor may be calcium influx via L-type calcium channels, and increased sensitivity to calcium of the contractile machinery via inhibition of myosin light chain phosphatase through activation of Rho-kinase. The importance of these findings for treatment of voiding dysfunction remains to be established.

• Bladder
• Signal Transduction
• Contractile Proteins
• Calcium Sensitivity
• Acetylcholine