Biomaterial Database

Modulation of the delayed K+ current by histamine in guinea pig ventricular myocytes. 1991

H Tanaka, and T Furukawa, and M Hayafuji, and Y Habuchi

Department of Laboratory Medicine, Kyoto Prefectural University of Medicine, Japan.

The effects of histamine on delayed K+ current (IK) were investigated in patch-clamped single guinea pig ventricular myocytes. Histamine increased IK with a maximal fractional response of 2.7 and a kd of 9.4 x 10(-7) mol/l. At a concentration of 10(-8) mol/l, histamine did not increase IK significantly, but increased ICa by 52% +/- 12%. The voltage-dependence of IK activation, the reversal potential and the time course of the IK tail decay were not changed by histamine. Under pretreatment with 10(-4) mol/l of ranitidine, neither histamine (10(-6) mol/l) nor 2-pyridylethylamine (10(-4) mol/l) caused any sizable increase in IK. When the cell was pretreated with a saturating dose of isoproterenol (10(-6) mol/l), histamine did not additively enhance IK. The IK enhancement by 3 x 10(-7) mol/l histamine was partially antagonized by concurrent exposure to 5 x 10(-6) mol/l carbachol. Whereas, use of a higher concentration of histamine (10(-6) mol/l) obscured the inhibitory effect of carbachol. It is concluded that histaminergic action of IK is attributed exclusively to H2 receptor-mediated reactions involving GS protein and adenylate cyclase.

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
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D011188	Potassium	An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
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
D002217	Carbachol	A slowly hydrolyzed CHOLINERGIC AGONIST that acts at both MUSCARINIC RECEPTORS and NICOTINIC RECEPTORS.	Carbamylcholine,Carbacholine,Carbamann,Carbamoylcholine,Carbastat,Carbocholine,Carboptic,Doryl,Isopto Carbachol,Jestryl,Miostat,Carbachol, Isopto
D004594	Electrophysiology	The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
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
D006321	Heart	The hollow, muscular organ that maintains the circulation of the blood.	Hearts
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
D000200	Action Potentials	Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.	Spike Potentials,Nerve Impulses,Action Potential,Impulse, Nerve,Impulses, Nerve,Nerve Impulse,Potential, Action,Potential, Spike,Potentials, Action,Potentials, Spike,Spike Potential