A Study On The Effect Of Adrenergic Receptors Stimulation On The Basal Tone And Contractile Response Of The Urinary Bladder In Rats

This stud’ was performed to identify the role of the varlet\ ofadrene,:gic receptors in the urinary bladder and clarify which of them is moreeffective in modulating the function of the lower urinary- tract to he used in thetreatment of bladder dysfunction. Moreover_ sex difference was considered as afactor to examine if a sex related difference exists in the magnitude of responseof the urinary bladder smooth muscle to adrenergic agonists.In order to achieve this aim this studs’ was done on a total number 0160adult healthy white albino rats. The animals were divided equally into 2 majorgroups according to sex (30 male and 30 female). Then each sex group w assubdivided into 5 equal subgroups (n=6). The whole bladder was excised. cutin both sides without separation to form one strip then mounted in TY rod’ssolution maintained at 37 °C and gassed with a mixture of 95% 0, and 5% CO,.To examine the stimulation effect of a and a-AR subtypes on the basal toneand Carbachol-induced contraction of the isolated rat urinary bladderrespectively. Phenylephrine (al-AR selective agonist). Clonidine (a—ARseleCtive agonist). Dobutamine ((3I-AR-selective agonist). Salbutamol ((3—ARselective agonist). and Norepinephrine 1133-AR agonist in the presence of.Phentolamine (a-AR blocker). plus Propranolol (p,—and (3, -ARs blockerl:were added to the isolated urinary bladder which vas connected to theuniversal kymograph.It was found that stimulation of a1-ARs with Phem lephrine wasassociated with a significant increase in the basal tone of rat isolated urinar\bladder which was significantly- higher in female rats than in male. Stimulationof of -ARs with Clonidine was not associated with any change in the basal toneof rat isolated urinary bladder.