Biomaterial Database

Alpha and beta adrenergic receptors of canine lung tissue identification and characterization of alpha adrenergic receptors by two different ligands. 1982

M Hasegawa, and R G Townley

Adrenergic receptors of canine peripheral lung tissues were measured by direct binding techniques using [3H]dihydroergocryptine ([3H]DHE), [3H]prazosin and [3H]dihydroalprenolol ([3H]DHA). All three ligands bound to canine lung tissue with saturability, stereospecificity and reversibility. Adrenergic agonists competed for binding of [3H]DHE and [3H]prazosin in the order: 1-epinephrine greater than 1-norepinephrine greater than d-epinephrine greater than d-norepinephrine greater than 1-isoproterenol. Adrenergic antagonists competed for binding of [3H]prazosin in the order: prazosin greater than phentolamine greater than yohimbine. Inhibition curves of [3H]DHE by prazosin or yohimbine were biphasic suggesting two subtypes of binding sites. Maximum binding capacities of [3H]DHE ranged from 30.6 to 42.7 fmol/mg protein. [3H]prazosin from 18.3 to 26.9 fmol/mg protein and [3H]DHA from 135.2 to 359.4 fmol/mg protein. When both [3H]DHE and [3H]prazosin were used in the same membrane preparation, specific binding of [3H]DHE was always more than that of [3H]prazosin. Since [3H]prazosin is considered to bind to alpha 1 adrenergic receptors specifically and [3H]DHE is considered to bind alpha 2 adrenergic receptors nonselectively, the difference between the numbers of the specific binding sites of these two ligands should represent alpha 2 adrenergic receptors. Alpha 2 adrenergic receptor density ranged from 9.5 to 21.1 fmol/mg protein. Our results suggest the existence of both alpha 1 and alpha 2 adrenergic receptors in canine peripheral lung tissue. Approximately 40% of alpha adrenergic receptors were alpha 2. The ratio of alpha/beta adrenergic receptors ranged from 1:3.3 to 1:10.4. The ratio of alpha 1/beta adrenergic receptors ranged from 1:6.7 to 1:21.1.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008168	Lung	Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.	Lungs
D011224	Prazosin	A selective adrenergic alpha-1 antagonist used in the treatment of HEART FAILURE; HYPERTENSION; PHEOCHROMOCYTOMA; RAYNAUD DISEASE; PROSTATIC HYPERTROPHY; and URINARY RETENTION.	Furazosin,Minipress,Pratsiol,Prazosin HCL,Prazosin Hydrochloride,HCL, Prazosin,Hydrochloride, Prazosin
D011869	Radioligand Assay	Quantitative determination of receptor (binding) proteins in body fluids or tissue using radioactively labeled binding reagents (e.g., antibodies, intracellular receptors, plasma binders).	Protein-Binding Radioassay,Radioreceptor Assay,Assay, Radioligand,Assay, Radioreceptor,Assays, Radioligand,Assays, Radioreceptor,Protein Binding Radioassay,Protein-Binding Radioassays,Radioassay, Protein-Binding,Radioassays, Protein-Binding,Radioligand Assays,Radioreceptor Assays
D011941	Receptors, Adrenergic	Cell-surface proteins that bind epinephrine and/or norepinephrine with high affinity and trigger intracellular changes. The two major classes of adrenergic receptors, alpha and beta, were originally discriminated based on their cellular actions but now are distinguished by their relative affinity for characteristic synthetic ligands. Adrenergic receptors may also be classified according to the subtypes of G-proteins with which they bind; this scheme does not respect the alpha-beta distinction.	Adrenergic Receptors,Adrenoceptor,Adrenoceptors,Norepinephrine Receptor,Receptors, Epinephrine,Receptors, Norepinephrine,Adrenergic Receptor,Epinephrine Receptors,Norepinephrine Receptors,Receptor, Adrenergic,Receptor, Norepinephrine
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
D011943	Receptors, Adrenergic, beta	One of two major pharmacologically defined classes of adrenergic receptors. The beta adrenergic receptors play an important role in regulating CARDIAC MUSCLE contraction, SMOOTH MUSCLE relaxation, and GLYCOGENOLYSIS.	Adrenergic beta-Receptor,Adrenergic beta-Receptors,Receptors, beta-Adrenergic,beta Adrenergic Receptor,beta-Adrenergic Receptor,beta-Adrenergic Receptors,Receptor, Adrenergic, beta,Adrenergic Receptor, beta,Adrenergic beta Receptor,Adrenergic beta Receptors,Receptor, beta Adrenergic,Receptor, beta-Adrenergic,Receptors, beta Adrenergic,beta Adrenergic Receptors,beta-Receptor, Adrenergic,beta-Receptors, Adrenergic
D004082	Dihydroalprenolol	Hydrogenated alprenolol derivative where the extra hydrogens are often tritiated. This radiolabeled form of ALPRENOLOL, a beta-adrenergic blocker, is used to label the beta-adrenergic receptor for isolation and study.	1-((Methylethyl)amino)-3-(2-propylphenoxy)-2-propanol
D004088	Dihydroergotoxine	A mixture of three different hydrogenated derivatives of ERGOTAMINE: DIHYDROERGOCORNINE; DIHYDROERGOCRISTINE; and DIHYDROERGOCRYPTINE. Dihydroergotoxine has been proposed to be a neuroprotective agent and a nootropic agent. The mechanism of its therapeutic actions is not clear, but it can act as an alpha-adrenergic antagonist and a dopamine agonist. The methanesulfonate salts of this mixture of alkaloids are called ERGOLOID MESYLATES.	Co-Dergocrine,Ergot Alkaloids, Hydrogenated,Dihydroergotoxin,Alkaloids, Hydrogenated Ergot,Hydrogenated Ergot Alkaloids
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