Action of autonomic drugs on the in vivo bladder base and proximal urethra in dog.
OBJECTIVE
To investigate the effects of autonomic drugs on the in vivo bladder base and proximal urethra in order to provide some reference materials for clinical usage of these drugs in the treatment of bladder outlet dysfunction.


METHODS
In 35 dogs, the bladder base was separated from the bladder body and closed to constitute a small chamber. The changes of the pressure in the bladder base chamber and proximal urethra were recorded synchronously before and after administration of autonomic drugs. All data were analyzed with Student's t test.


RESULTS
The bladder base had little response to acetylcholine (Ach) which however promoted a contraction of the proximal urethra. The effect of Ach on the proximal urethra was antagonized by phentolamine, but not by atropine. Isoprenaline resulted in relaxation of the bladder base, though it had little effect on the urethra. Norepinephrine (NE) produced contraction of the bladder base and urethra, while phentolamine caused a reduction in the bladder base and urethral pressure, and blocked the response of the bladder outlet region to NE. Angiotensin amide (AII) caused contraction of the bladder base and urethra, which was not obliterated by phentolamine.


CONCLUSIONS
The cholinergic drug has no influence on the in vivo canine bladder base, but causes a contraction of the proximal urethra through indirect activation of alpha-receptors. The alpha-adrenergic agents have great effects on the bladder base and urethra by acting on alpha-receptors within the musculature in the outlet region. The beta-adrenoceptor agonist results in relaxation of the bladder base, but it has no effect on the urethra.
Ye
G
G
Department of Urology, Newbridge Hospital, Third Military Medical University, Chongqing, China.
Jin
X
X
D000109:Acetylcholine / Q000494:pharmacology; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000818:Animals; D004285:Dogs; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D009638:Norepinephrine / Q000494:pharmacology; D014521:Urethra / Q000187:drug effects*; D001743:Urinary Bladder / Q000187:drug effects*
D000316:Adrenergic alpha-Agonists; D000318:Adrenergic beta-Agonists; D000109:Acetylcholine; D009638:Norepinephrine