The quantitative difference in adrenergic alpha-1, alpha-2 and beta receptors between the prostatic and epididymal ends of dog vas deferens

In order to study the regional differences in the distribution of adrenergic receptors of the vas deferens, we measured the amounts of adrenergic alpha-1, alpha-2 and beta receptors in prostatic, intermediate, and epididymal portions of the dog vas deferens using radioligand binding techniques. Saturation experiments with 3H-prazosin, 3H-yohimbine, and 3H-dihydroxy-alprenolol demonstrated that there were significant amounts of adrenergic alpha-1, alpha-2, and beta receptors, respectively, in these three portions. alpha-1 receptors existed most densely in the whole vas deferens. The prostatic portion was found to have the largest amounts of alpha-1 and alpha-2 receptors among three portions studied. beta-Receptors were distributed most densely in the intermediate portion. alpha-1, alpha-2, and beta adrenergic receptors show different distribution patterns throughout the whole length of vas deferens.