Serotonergic regulation of distention-induced ATP release from the urothelium.

Serotonergic regulation of distention-induced ATP release from the urothelium. Am J Physiol Renal Physiol. 2015 Nov 18;:ajprenal.00024.2015 Authors: Matsumoto-Miyai K, Yamada E, Shinzawa E, Koyama Y, Shimada S, Yoshizumi M, Kawatani M Abstract 5-hydroxytryptamine (5-HT; serotonin) is involved in both motor and sensory functions in hollow organs, especially the gastrointestinal tract. However, the involvement of 5-HT in visceral sensation of the urinary bladder remains unknown. Because distention-induced ATP release from the urothelium plays an essential role in visceral sensation of the urinary bladder, we investigated regulation of urothelial ATP release by the 5-HT signaling system. RT-PCR and immunohistochemical analyses of the urothelium revealed specific expression of 5-HT1D and 5-HT4 receptors. Addition of 5-HT did not affect urothelial ATP release without bladder distention, but it significantly reduced distention-induced ATP release by physiological pressure during urine storage (5 cmH2O). The inhibitory effect of 5-HT on distention-elicited ATP release was blocked by preincubation with the 5-HT1B/1D antagonist GR127935, but not by the 5-HT4 antagonist SB204070. The mRNA encoding tryptophan hydroxylase 1 was detected in the urinary bladder by nested RT-PCR amplification, and L-tryptophan or the selective serotonin reuptake inhibitor citalopram also inhibited ATP release, indicating that 5-HT is endogenously synthesized and re...
Source: Am J Physiol Renal P... - Category: Urology & Nephrology Authors: Tags: Am J Physiol Renal Physiol Source Type: research