Biomaterial Database

Irreversible antagonism of histamine H2 receptors in guinea-pig myocardium. 1986

K M MacLeod, and D Wenkstern, and J H McNeill

Dissociation constants and receptor reserves for histamine acting at H2 receptors in guinea-pig right atria and papillary muscles were measured using the irreversible H2 receptor antagonist L-643,441. Histamine alone was less potent in papillary muscles than in right atria, and maximum responses of papillary muscles to histamine were more susceptible to depression by L-643,441 than were maximum responses of right atria. However, dissociation constants (-log KA values) for histamine calculated using 3 different doses of L-643,441 were 0.5 log unit greater in papillary muscles than in right atria. A more marked difference was found in the estimates of receptor reserve for histamine, which appeared to be much greater in right atria than papillary muscles.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009200	Myocardial Contraction	Contractile activity of the MYOCARDIUM.	Heart Contractility,Inotropism, Cardiac,Cardiac Inotropism,Cardiac Inotropisms,Contractilities, Heart,Contractility, Heart,Contraction, Myocardial,Contractions, Myocardial,Heart Contractilities,Inotropisms, Cardiac,Myocardial Contractions
D009206	Myocardium	The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.	Muscle, Cardiac,Muscle, Heart,Cardiac Muscle,Myocardia,Cardiac Muscles,Heart Muscle,Heart Muscles,Muscles, Cardiac,Muscles, Heart
D010210	Papillary Muscles	Conical muscular projections from the walls of the cardiac ventricles, attached to the cusps of the atrioventricular valves by the chordae tendineae.	Muscle, Papillary,Muscles, Papillary,Papillary Muscle
D011968	Receptors, Histamine	Cell-surface proteins that bind histamine and trigger intracellular changes influencing the behavior of cells. Histamine receptors are widespread in the central nervous system and in peripheral tissues. Three types have been recognized and designated H1, H2, and H3. They differ in pharmacology, distribution, and mode of action.	Histamine Binding Sites,Histamine Receptors,Histamine Receptor,Binding Sites, Histamine,Receptor, Histamine,Sites, Histamine Binding
D011970	Receptors, Histamine H2	A class of histamine receptors discriminated by their pharmacology and mode of action. Histamine H2 receptors act via G-proteins to stimulate ADENYLYL CYCLASES. Among the many responses mediated by these receptors are gastric acid secretion, smooth muscle relaxation, inotropic and chronotropic effects on heart muscle, and inhibition of lymphocyte function. (From Biochem Soc Trans 1992 Feb;20(1):122-5)	Histamine H2 Receptors,H2 Receptors,Receptors, H2,H2 Receptors, Histamine
D005260	Female		Females
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
D006632	Histamine	An amine derived by enzymatic decarboxylation of HISTIDINE. It is a powerful stimulant of gastric secretion, a constrictor of bronchial smooth muscle, a vasodilator, and also a centrally acting neurotransmitter.	Ceplene,Histamine Dihydrochloride,Histamine Hydrochloride,Peremin
D006635	Histamine H2 Antagonists	Drugs that selectively bind to but do not activate histamine H2 receptors, thereby blocking the actions of histamine. Their clinically most important action is the inhibition of acid secretion in the treatment of gastrointestinal ulcers. Smooth muscle may also be affected. Some drugs in this class have strong effects in the central nervous system, but these actions are not well understood.	Antihistaminics, H2,H2 Receptor Blockader,Histamine H2 Antagonist,Histamine H2 Blocker,Histamine H2 Receptor Antagonist,Histamine H2 Receptor Antagonists,Histamine H2 Receptor Blockader,Histamine H2 Receptor Blockaders,Antagonists, Histamine H2,Blockaders, Histamine H2 Receptor,H2 Receptor Blockaders,Histamine H2 Blockers,Receptor Antagonists, Histamine H2,Receptor Blockaders, H2,Antagonist, Histamine H2,Blockader, H2 Receptor,Blockaders, H2 Receptor,Blocker, Histamine H2,Blockers, Histamine H2,H2 Antagonist, Histamine,H2 Antagonists, Histamine,H2 Antihistaminics,H2 Blocker, Histamine,H2 Blockers, Histamine,Receptor Blockader, H2