Role of adrenoceptors in the proximal urethral function of female and male rabbits using an in vivo model of isovolumetric pressure generation.
The role of alpha-1 and alpha-2 adrenoceptors in the contractile response of the proximal urethra to agonists and antagonists was studies in female and male New Zealand White rabbits. The response pattern for alpha-1 agonists showed a sharp rise, while that for alpha-2 agonists showed a gradual increase to a maximum pressure. The duration of the response of alpha-2 agonists was significantly longer than that of alpha-1 agonists. A difference in the response between alpha-1 and alpha-2 would be produced mainly through different receptor functions. The magnitude of the response of alpha-1 adrenoceptors in the male rabbits was almost twice that of the female rabbits. In contrast, the response of alpha-2 in the male rabbits was less than that of the female rabbits. Our experimental findings indicate that alpha-2 stimulation mediates a slow and prolonged response that is essential for urinary continence in female rabbits.
Yamaguchi
T
T
Department of Urology, Miyazaki Medical College, Japan.
Kitada
S
S
Osada
Y
Y
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003000:Clonidine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D010656:Phenylephrine / Q000494:pharmacology; D011224:Prazosin / Q000494:pharmacology; D011312:Pressure; D011817:Rabbits; D011942:Receptors, Adrenergic, alpha / Q000502:physiology*; D011943:Receptors, Adrenergic, beta / Q000502:physiology*; D014521:Urethra / Q000187:drug effects / Q000294:innervation* / Q000502:physiology*
D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D010656:Phenylephrine; D007545:Isoproterenol; D003000:Clonidine; D011224:Prazosin