QUANTITATIVE-ANALYSIS OF ALPHA-ADRENERGIC AND BETA-ADRENERGIC-RECEPTOR DENSITIES IN THE LOWER URINARY-TRACT OF THE DOG AND THE RABBIT

  • 1 January 1979
    • journal article
    • research article
    • Vol. 17  (1) , 75-77
Abstract
Using specific radioligand receptor binding assays, both .alpha.- and .beta.-adrenergic receptors were quantitated in the musculature of the lower ureter, bladder body, posterior bladder base, and proximal urethra of the dog, and in the bladder base and body of the rabbit. For the .beta. receptor assay 3H-dihydroalprenolol [DHA] was used as the ligand, and, for the .alpha. receptor assay, 3H-dihydroergocryptine [DHE] was used. In the dog, there was a significantly greater density of .beta. receptors in the bladder body than in either the ureter or the posterior bladder base. The urethra had an intermediate density. The bladder base and the proximal urethra had a significantly greater density of .alpha. receptors than either the ureter or the bladder dome. The dissociation constant of .beta. receptors for DHA was approximately 9 nM for all tissues studied, and that of .alpha. receptors for DHE approximately 7 nM. A similar distribution of .alpha.- and .beta. adrenergic receptors was seen in the rabbit bladder.