Biomaterial Database

Effects of 2-nicotinamidoethyl nitrate (Nicorandil) on excitation-contraction coupling in the smooth muscle cells of rabbit ear artery. 1984

M Kajiwara, and G Droogmans, and R Casteels

The effect of SG-75 (Nicorandil) on the neuromuscular transmission and smooth muscle membrane of the rabbit ear artery was investigated by means of intracellular microelectrodes, isometric tension recording and flux experiments. This agent caused a pronounced hyperpolarization of the cell membrane and a significant increase of the K-permeability. During perivascular nerve stimulation, the amplitude and the time constant of the falling phase of the excitatory junction potentials were reduced, causing a suppression of spike generation and of the concomitant contractile responses, but the release of [3H]noradrenaline was not affected. At high doses this agent inhibited significantly submaximal contractile responses induced by various stimuli. However, these effects could not be correlated with changes in 45Ca fluxes. It is suggested that although the effect of SG-75 could be due mainly to an increase of the K-permeability and the concomitant hyperpolarization, it might also reduce the force development by a mechanism which does not depend on a reduction of the concentration of ionized Ca in the cytoplasm.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008564	Membrane Potentials	The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).	Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D009119	Muscle Contraction	A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.	Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
D009131	Muscle, Smooth, Vascular	The nonstriated involuntary muscle tissue of blood vessels.	Vascular Smooth Muscle,Muscle, Vascular Smooth,Muscles, Vascular Smooth,Smooth Muscle, Vascular,Smooth Muscles, Vascular,Vascular Smooth Muscles
D009536	Niacinamide	An important compound functioning as a component of the coenzyme NAD. Its primary significance is in the prevention and/or cure of blacktongue and PELLAGRA. Most animals cannot manufacture this compound in amounts sufficient to prevent nutritional deficiency and it therefore must be supplemented through dietary intake.	Nicotinamide,Vitamin B 3,Vitamin PP,3-Pyridinecarboxamide,Enduramide,Nicobion,Nicotinsäureamid Jenapharm,Papulex,Vitamin B3,3 Pyridinecarboxamide,B 3, Vitamin,B3, Vitamin,Jenapharm, Nicotinsäureamid
D009638	Norepinephrine	Precursor of epinephrine that is secreted by the ADRENAL MEDULLA and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers, and of the diffuse projection system in the brain that arises from the LOCUS CERULEUS. It is also found in plants and is used pharmacologically as a sympathomimetic.	Levarterenol,Levonorepinephrine,Noradrenaline,Arterenol,Levonor,Levophed,Levophed Bitartrate,Noradrenaline Bitartrate,Noradrénaline tartrate renaudin,Norepinephrin d-Tartrate (1:1),Norepinephrine Bitartrate,Norepinephrine Hydrochloride,Norepinephrine Hydrochloride, (+)-Isomer,Norepinephrine Hydrochloride, (+,-)-Isomer,Norepinephrine d-Tartrate (1:1),Norepinephrine l-Tartrate (1:1),Norepinephrine l-Tartrate (1:1), (+,-)-Isomer,Norepinephrine l-Tartrate (1:1), Monohydrate,Norepinephrine l-Tartrate (1:1), Monohydrate, (+)-Isomer,Norepinephrine l-Tartrate (1:2),Norepinephrine l-Tartrate, (+)-Isomer,Norepinephrine, (+)-Isomer,Norepinephrine, (+,-)-Isomer
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.
D011817	Rabbits	A burrowing plant-eating mammal with hind limbs that are longer than its fore limbs. It belongs to the family Leporidae of the order Lagomorpha, and in contrast to hares, possesses 22 instead of 24 pairs of chromosomes.	Belgian Hare,New Zealand Rabbit,New Zealand Rabbits,New Zealand White Rabbit,Rabbit,Rabbit, Domestic,Chinchilla Rabbits,NZW Rabbits,New Zealand White Rabbits,Oryctolagus cuniculus,Chinchilla Rabbit,Domestic Rabbit,Domestic Rabbits,Hare, Belgian,NZW Rabbit,Rabbit, Chinchilla,Rabbit, NZW,Rabbit, New Zealand,Rabbits, Chinchilla,Rabbits, Domestic,Rabbits, NZW,Rabbits, New Zealand,Zealand Rabbit, New,Zealand Rabbits, New,cuniculus, Oryctolagus
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D004423	Ear	The hearing and equilibrium system of the body. It consists of three parts: the EXTERNAL EAR, the MIDDLE EAR, and the INNER EAR. Sound waves are transmitted through this organ where vibration is transduced to nerve signals that pass through the ACOUSTIC NERVE to the CENTRAL NERVOUS SYSTEM. The inner ear also contains the vestibular organ that maintains equilibrium by transducing signals to the VESTIBULAR NERVE.	Vestibulocochlear System,Vestibulocochlear Apparatus,Apparatus, Vestibulocochlear,Ears,System, Vestibulocochlear