Biomaterial Database

Relationship between alpha 2-adrenoceptor occupancy and response for B-HT 933 in canine saphenous vein. 1985

R R Ruffolo, and R L Zeid

The relationship between alpha 2-adrenoceptor occupancy and contractile response for B-HT 933 was investigated in canine saphenous vein. B-HT 933 produced a concentration-dependent, alpha 2-adrenoceptor mediated contractile response in canine saphenous vein with an ED50 of 0.65 microM. The dissociation constant (KA) of B-HT 933 was calculated to be 5 microM. The relationship between alpha 2-adrenoceptor occupancy and contractile response for B-HT 933 in canine saphenous vein was hyperbolic, typical of full agonists or agonists with high intrinsic efficacies. B-HT 933 produced a half-maximal response in canine saphenous vein at only 11% alpha 2-adrenoceptor occupancy, with a maximal response being obtained with 40-60% alpha 2-adrenoceptor occupancy. We conclude that the selective alpha 2-adrenoceptor agonist, B-HT 933, has high efficacy at alpha 2-adrenoceptors, such that a significant alpha 2-adrenoceptor reserve, or spare alpha 2-adrenoceptors, exists for this compound in canine saphenous vein.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D011942	Receptors, Adrenergic, alpha	One of the two major pharmacological subdivisions of adrenergic receptors that were originally defined by the relative potencies of various adrenergic compounds. The alpha receptors were initially described as excitatory receptors that post-junctionally stimulate SMOOTH MUSCLE contraction. However, further analysis has revealed a more complex picture involving several alpha receptor subtypes and their involvement in feedback regulation.	Adrenergic alpha-Receptor,Adrenergic alpha-Receptors,Receptors, alpha-Adrenergic,alpha-Adrenergic Receptor,alpha-Adrenergic Receptors,Receptor, Adrenergic, alpha,Adrenergic alpha Receptor,Adrenergic alpha Receptors,Receptor, alpha-Adrenergic,Receptors, alpha Adrenergic,alpha Adrenergic Receptor,alpha Adrenergic Receptors,alpha-Receptor, Adrenergic,alpha-Receptors, Adrenergic
D004285	Dogs	The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)	Canis familiaris,Dog
D004305	Dose-Response Relationship, Drug	The relationship between the dose of an administered drug and the response of the organism to the drug.	Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
D005260	Female		Females
D000316	Adrenergic alpha-Agonists	Drugs that selectively bind to and activate alpha adrenergic receptors.	Adrenergic alpha-Receptor Agonists,alpha-Adrenergic Receptor Agonists,Adrenergic alpha-Agonist,Adrenergic alpha-Receptor Agonist,Receptor Agonists, Adrenergic alpha,Receptor Agonists, alpha-Adrenergic,alpha-Adrenergic Agonist,alpha-Adrenergic Agonists,alpha-Adrenergic Receptor Agonist,Adrenergic alpha Agonist,Adrenergic alpha Agonists,Adrenergic alpha Receptor Agonist,Adrenergic alpha Receptor Agonists,Agonist, Adrenergic alpha-Receptor,Agonist, alpha-Adrenergic,Agonist, alpha-Adrenergic Receptor,Agonists, Adrenergic alpha-Receptor,Agonists, alpha-Adrenergic,Agonists, alpha-Adrenergic Receptor,Receptor Agonist, alpha-Adrenergic,Receptor Agonists, alpha Adrenergic,alpha Adrenergic Agonist,alpha Adrenergic Agonists,alpha Adrenergic Receptor Agonist,alpha Adrenergic Receptor Agonists,alpha-Agonist, Adrenergic,alpha-Agonists, Adrenergic,alpha-Receptor Agonist, Adrenergic,alpha-Receptor Agonists, Adrenergic
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001381	Azepines	Seven membered heterocyclic rings containing a NITROGEN atom.	Hexamethyleneimines
D012501	Saphenous Vein	The vein which drains the foot and leg.	Saphenous Veins,Vein, Saphenous,Veins, Saphenous
D014661	Vasoconstriction	The physiological narrowing of BLOOD VESSELS by contraction of the VASCULAR SMOOTH MUSCLE.	Vasoconstrictions