Role of adrenoceptors in the proximal urethral function of female and male rabbits using an in vivo model of isovolumetric pressure generation

Abstract

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.