Characterization of alpha1-adrenoceptor subtypes in the pig.
The identities of the alpha1-adrenoceptor subtypes present in various tissues of the pig were studied using [3H]prazosin radioligand binding. The subtypes were characterized by performing competition experiments for various subtype selective drugs. In the cerebral cortex, spleen and heart, both alpha1A- and alpha1B-adrenoceptors were detected. In the liver was found only the alpha1A-subtype, while in the aorta was found only the alpha1B-subtype. An alpha1-adrenoceptor subtype was present in the adrenal gland with a high affinity for prazosin, the pKd value being 9.6, but with relatively low affinities for other alpha1-adrenoceptor binding drugs. The adrenal gland alpha1-adrenoceptor did not seem to represent the classical alpha1D-subtype, since drugs selective for the alpha1D-subtype in other species, including BMY7378 and SKF104856, showed low affinities for the pig adrenal gland alpha1-adrenoceptor.
Wikberg-Matsson
A
A
Department of Ophthalmology, Academic Hospital, Uppsala University, Sweden.
Wikberg
J E
JE
Uhlén
S
S
D000311:Adrenal Glands / Q000378:metabolism; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000378:metabolism; D001667:Binding, Competitive / Q000187:drug effects; D002540:Cerebral Cortex / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008566:Membranes / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D011224:Prazosin / Q000494:pharmacology; D011869:Radioligand Assay; D018340:Receptors, Adrenergic, alpha-1 / Q000145:classification / Q000187:drug effects / Q000378:metabolism*; D013154:Spleen / Q000378:metabolism; D013552:Swine
D000317:Adrenergic alpha-Antagonists; D018340:Receptors, Adrenergic, alpha-1; D011224:Prazosin