Contractile responses of rabbit bladder neck to adrenaline, acetylcholine and papaverine after doxazosin treatment.

It has been demonstrated that long-term administration of doxazosin, an alpha 1 adrenoceptor antagonist, causes an up-regulation in the expression of alpha 1 adrenoceptor subtype mRNAs in the rat genitourinary tract. The aim of this study is to determine whether this up-regulation does have any effect on contractile response of rabbit bladder neck to adrenaline, acethylcholine and papaverin after long-term doxazosin treatment. Fourteen rabbits, treated with doxazosin 3 mg/kg/day p.o for 6 months, and were fed with a diet of standard laboratory rabbit chow (100 g/kg/day). Ten rabbits received the same amount of regular chow but no drug. Contractile responses of rabbit bladder neck to adrenaline acethylcholine and papaverine were measured.