The effect of bladder outlet obstruction on alpha1- and beta-adrenoceptor expression and function

Area of Science:

• Urology
• Pharmacology
• Physiology

Background:

• Bladder dysfunction is a common complication of bladder outlet obstruction (BOO).
• Adrenoceptor subtypes play a crucial role in bladder function.
• Changes in adrenoceptor expression or function may underlie BOO-induced bladder dysfunction.

Purpose of the Study:

• To investigate alterations in alpha(1)- and beta-adrenoceptor subtype expression and function in a rat model of BOO.
• To determine if these adrenoceptor changes contribute to bladder dysfunction.

Main Methods:

• Bladder outlet obstruction (BOO) was surgically induced in rats.
• Contraction and relaxation experiments were performed on isolated bladder strips.
• Quantitative real-time PCR was used to assess adrenoceptor mRNA expression.

Main Results:

• Relaxation responses to beta-adrenoceptor agonists were generally preserved, except for attenuation with BRL 37,344.
• Noradrenaline induced concentration-dependent contraction and relaxation in BOO rats, unlike control rats.
• Alpha(1D)-adrenoceptor mRNA expression was significantly increased in BOO rats.

Conclusions:

• While overall alpha(1)- and beta-adrenoceptor agonist responses are not drastically altered, noradrenaline's effect shifts in BOO.
• This shift involves alpha(1)-adrenoceptor-mediated contraction, potentially due to up-regulated alpha(1D)-adrenoceptors.
• These findings suggest a role for alpha(1D)-adrenoceptor changes in BOO-related bladder dysfunction.