Expression of Muscarinic M sub 3 -Receptors Coupled to Inositol Phospholipid Hydrolysis in Human Detrusor Cultured Smooth Muscle Cells

Abstract

These results indicate that human detrusor smooth muscle cells in culture express M3 muscarinic receptors which are linked to phosphoinositide hydrolysis.

The M2 muscarinic receptor mediates in vitro bladder contractions from patients with neurogenic bladder dysfunction

“…Reported affinity ranges for the M2 subtype is shaded with horizontal lines, and reported affinity for the M3 subtype is shaded with vertical lines. Symbols refer to the affinities that were determined by Schild analysis of the bladder tissue obtained from the individual patient numbers indicated in Table 1. muscle cells have demonstrated greater numbers of M 2 than M 3 receptors (27,28,32,33,39). The mRNA encoding M 2 and M 3 has been reported to be present in equal amounts (50).…”

Comparative pharmacological analysis of Rho-kinase inhibitors and identification of molecular components of Ca2+ sensitization in the rat lower urinary tract

“…These regulatory actions are mediated through the interaction of norepinephrine (sympathetic component released by hypogastric nerve stimulation), acetylcholine and ATP (parasympathetic components released by pelvic nerve stimulation) with adrenergic, muscarinic and purinergic receptors, respectively [2]. Stimulation of M 2 and M 3 muscarinic receptors produce detrusor smooth muscle contraction [4][5][6][7], whereas sympathetic activation of post-junctional α 1 -adrenoceptors in the urethra and bladder trigone plays a key role in the maintenance of urethral closure pressure [4,[8][9][10]. In addition, β 2 -and β 3 -adrenoceptors mediate relaxation of rat and human detrusor, causing bladder activity inhibition [11][12][13].…”

The Importance of the Cholinergic System in Neurourology

“…Despite a predominance of m 2 receptors in human and animal detrusor, several investigators have found that the pharmacologically defined M 3 receptor mediates bladder contraction [7]. Cultured human detrusor cells expressed M 3 receptors linked to phosphoinositide hydrolysis [13]. Recently, however, also M 2 receptors were shown to be able to mediate rat bladder contraction in vitro as well as in vivo by reversing β-adrenoceptor-mediated relaxation [16].…”