Biomaterial Database

Alpha 2-adrenoceptor in HT29 human colon adenocarcinoma cell-line: study of [3H](-)-adrenaline binding. 1989

J M Sénard, and P Mauriège, and D Daviaud, and H Paris

INSERM U-317, Institut de Physiologie, Université Paul Sabatier, Toulouse, France.

The HT29 human adenocarcinoma cell-line was used to investigate the binding of [3H](-)-adrenaline at alpha 2-adrenoceptors. All aspects of the study indicated that alpha 2-adrenoceptors were specifically labeled. [3H](-)-adrenaline bound with high affinity (KD = 2.28 +/- 0.41 nM) to a single population of non-interacting sites. The rank order of adrenoceptor antagonists (yohimbine greater than phentolamine much greater than prazosin) and agonists (UK-14,304 greater than clonidine greater than (-)-adrenaline greater than (-)-noradrenaline greater than (+)-adrenaline greater than (+)-noradrenaline greater than amidephrine) to compete with [3H](-)-adrenaline binding showed that the labeled sites were alpha 2-selective and stereospecific. Comparison of the binding parameters of [3H](-)-adrenaline with those of [3H]clonidine (partial-agonist) and [3H]yohimbine (antagonist) indicated that [3H](-)-adrenaline and [3H]clonidine labeled a similar number of sites (156 +/- 13 versus 175 +/- 21 fmol/mg protein) and that [3H]yohimbine (Bmax = 246 +/- 22 fmol/mg protein) labeled more sites than the 3H-agonists. Data on the inhibition of [3H]yohimbine binding by (-)-adrenaline was better fitted to a two-site model and revealed (1) that the KiL/KiH ratio was higher for (-)-adrenaline than for clonidine (2) that both agonists recognized the same percentage of high-affinity receptors. The results from a kinetic study of [3H](-)-adrenaline binding were apparently inconsistent with the equilibrium data. Both the association and dissociation were bi-exponential, suggesting a relative heterogeneity of the labeled sites. The tritiated physiological full-agonist was moreover able to induce tight-binding. The practical consequences of this property are discussed.

UI	MeSH Term	Description	Entries
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
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D003000	Clonidine	An imidazoline sympatholytic agent that stimulates ALPHA-2 ADRENERGIC RECEPTORS and central IMIDAZOLINE RECEPTORS. It is commonly used in the management of HYPERTENSION.	Catapres,Catapresan,Catapressan,Chlophazolin,Clofelin,Clofenil,Clonidine Dihydrochloride,Clonidine Hydrochloride,Clonidine Monohydrobromide,Clonidine Monohydrochloride,Clopheline,Dixarit,Gemiton,Hemiton,Isoglaucon,Klofelin,Klofenil,M-5041T,ST-155,Dihydrochloride, Clonidine,Hydrochloride, Clonidine,M 5041T,M5041T,Monohydrobromide, Clonidine,Monohydrochloride, Clonidine,ST 155,ST155
D003110	Colonic Neoplasms	Tumors or cancer of the COLON.	Cancer of Colon,Colon Adenocarcinoma,Colon Cancer,Cancer of the Colon,Colon Neoplasms,Colonic Cancer,Neoplasms, Colonic,Adenocarcinoma, Colon,Adenocarcinomas, Colon,Cancer, Colon,Cancer, Colonic,Cancers, Colon,Cancers, Colonic,Colon Adenocarcinomas,Colon Cancers,Colon Neoplasm,Colonic Cancers,Colonic Neoplasm,Neoplasm, Colon,Neoplasm, Colonic,Neoplasms, Colon
D004837	Epinephrine	The active sympathomimetic hormone from the ADRENAL MEDULLA. It stimulates both the alpha- and beta- adrenergic systems, causes systemic VASOCONSTRICTION and gastrointestinal relaxation, stimulates the HEART, and dilates BRONCHI and cerebral vessels. It is used in ASTHMA and CARDIAC FAILURE and to delay absorption of local ANESTHETICS.	Adrenaline,4-(1-Hydroxy-2-(methylamino)ethyl)-1,2-benzenediol,Adrenaline Acid Tartrate,Adrenaline Bitartrate,Adrenaline Hydrochloride,Epifrin,Epinephrine Acetate,Epinephrine Bitartrate,Epinephrine Hydrochloride,Epinephrine Hydrogen Tartrate,Epitrate,Lyophrin,Medihaler-Epi,Acetate, Epinephrine
D006165	Guanylyl Imidodiphosphate	A non-hydrolyzable analog of GTP, in which the oxygen atom bridging the beta to the gamma phosphate is replaced by a nitrogen atom. It binds tightly to G-protein in the presence of Mg2+. The nucleotide is a potent stimulator of ADENYLYL CYCLASES.	GMP-PNP,GMP-P(NH)P,Gpp(NH)p,Guanosine 5'-(Beta,Gamma-Imido)Triphosphate,Guanyl-5'-Imidodiphosphate,P(NH)PPG,Guanyl 5' Imidodiphosphate,Imidodiphosphate, Guanylyl
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000230	Adenocarcinoma	A malignant epithelial tumor with a glandular organization.	Adenocarcinoma, Basal Cell,Adenocarcinoma, Granular Cell,Adenocarcinoma, Oxyphilic,Adenocarcinoma, Tubular,Adenoma, Malignant,Carcinoma, Cribriform,Carcinoma, Granular Cell,Carcinoma, Tubular,Adenocarcinomas,Adenocarcinomas, Basal Cell,Adenocarcinomas, Granular Cell,Adenocarcinomas, Oxyphilic,Adenocarcinomas, Tubular,Adenomas, Malignant,Basal Cell Adenocarcinoma,Basal Cell Adenocarcinomas,Carcinomas, Cribriform,Carcinomas, Granular Cell,Carcinomas, Tubular,Cribriform Carcinoma,Cribriform Carcinomas,Granular Cell Adenocarcinoma,Granular Cell Adenocarcinomas,Granular Cell Carcinoma,Granular Cell Carcinomas,Malignant Adenoma,Malignant Adenomas,Oxyphilic Adenocarcinoma,Oxyphilic Adenocarcinomas,Tubular Adenocarcinoma,Tubular Adenocarcinomas,Tubular Carcinoma,Tubular Carcinomas
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