Life Sciences Commons^™

Objective - To investigate the role of adrenoceptor subtypes in regulating the spontaneous contractile activity of the inner lining of the urinary bladder (urothelium/lamina propria).

Materials and Methods - The responses of isolated strips of porcine urothelium/lamina propria to noradrenaline, phenylephrine, and isoprenaline were obtained in the absence and presence of receptor subtype-selective antagonists. Quantitative reverse-transcriptase polymerase chain reaction was undertaken to assess the expression of adrenoceptor genes.

Results - The tissues expressed all α1- and β-adrenoceptor subtypes, with the α1A-, α1B-, and β2-adrenoceptors the predominant receptors at the messenger RNA level. In the functional experiments, the rate of phasic …

Objective: To investigate the effects of tissue stretch and muscarinic receptor stimulation on the spontaneous activity of the urothelium/lamina propria and identify the specific receptor subtype mediating these responses.

Methods: Isolated strips of porcine urothelium with lamina propria were set up for in vitro recording of contractile activity. Muscarinic receptor subtype-selective antagonists were used to identify the receptors influencing the contractile rate responses to stretch and stimulation with carbachol.

Results: Isolated strips of urothelium with lamina propria developed spontaneous contractions (3.7 cycles/min) that were unaffected by tetrodotoxin, N_-nitro-L-arginine, or indomethacin. Carbachol (1 _M) increased the spontaneous contractile …