Biomaterial Database

Relationship between intrinsic activity of beta-adrenoceptor agonist and amount of spare receptors in guinea pig taenia caecum. 1983

K Koike, and I Takayanagi

Beta-adrenoceptor mechanisms were studied in the isolated guinea-pig taenia caecum. Isoprenaline, desisopropylprocaterol and carteolol relaxed guinea-pig taenia caecum, and their intrinsic activities (mean +/- S.E.) were 1.0, 0.95 +/- 0.03 and 0.61 +/- 0.08, respectively. The pD2 values (mean +/- S.E.) were 8.59 +/- 0.06 for isoprenaline, 7.94 +/- 0.21 for desisopropylprocaterol and 6.35 +/- 0.14 for carteolol. The beta-adrenoceptors in guinea-pig taenia caecum were irreversibly inactivated by photoaffinity labeling with isoprenaline (6 X 10(-6) M). Photoinactivation of beta-adrenoceptors caused a considerable parallel shift in the dose-response curve of isoprenaline. The decline of the dose-response curves of desisopropylprocaterol and carteolol without a preceding shift was observed after photoinactivation. Isoprenaline, desisopropylprocaterol and carteolol increased cyclic AMP levels in guinea-pig taenia caecum, and the pD2 values were 7.43, 6.97 and 5.96, respectively. When differences between the pD2 values for test drugs obtained from the mechanical responses and from the increases of cyclic AMP levels were calculated, the differences for isoprenaline was larger than those for desisopropylprocaterol and carteolol. The dose-response curves for relaxation and cyclic AMP level by isoprenaline were both shifted to the right as a result of prior incubation with carteolol. These results suggest that there are spare receptors for isoprenaline, but few for desisopropylprocaterol and carteolol in the smooth muscle.

UI	MeSH Term	Description	Entries
D007545	Isoproterenol	Isopropyl analog of EPINEPHRINE; beta-sympathomimetic that acts on the heart, bronchi, skeletal muscle, alimentary tract, etc. It is used mainly as bronchodilator and heart stimulant.	Isoprenaline,Isopropylarterenol,4-(1-Hydroxy-2-((1-methylethyl)amino)ethyl)-1,2-benzenediol,Euspiran,Isadrin,Isadrine,Isopropyl Noradrenaline,Isopropylnoradrenaline,Isopropylnorepinephrine,Isoproterenol Hydrochloride,Isoproterenol Sulfate,Isuprel,Izadrin,Norisodrine,Novodrin,Hydrochloride, Isoproterenol,Noradrenaline, Isopropyl,Sulfate, Isoproterenol
D008297	Male		Males
D009126	Muscle Relaxation	That phase of a muscle twitch during which a muscle returns to a resting position.	Muscle Relaxations,Relaxation, Muscle,Relaxations, Muscle
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
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
D002354	Carteolol	A beta-adrenergic antagonist used as an anti-arrhythmia agent, an anti-angina agent, an antihypertensive agent, and an antiglaucoma agent.	Carteolol Hydrochloride,Carteolol Monohydrochloride,OPC-1085,Hydrochloride, Carteolol,Monohydrochloride, Carteolol,OPC 1085,OPC1085
D002432	Cecum	The blind sac or outpouching area of the LARGE INTESTINE that is below the entrance of the SMALL INTESTINE. It has a worm-like extension, the vermiform APPENDIX.	Cecums
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
D004983	Ethanolamines	AMINO ALCOHOLS containing the ETHANOLAMINE; (-NH2CH2CHOH) group and its derivatives.	Aminoethanols
D006168	Guinea Pigs	A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.	Cavia,Cavia porcellus,Guinea Pig,Pig, Guinea,Pigs, Guinea