Biomaterial Database

Inhibitory properties of NIP-121, a potassium channel opener, on high potassium- and norepinephrine-induced contraction and calcium mobilization in rat aorta. 1994

T Yamashita, and Y Masuda, and S Tanaka

Shiraoka Research Station of Biological Science, Nissan Chemical Industries, Saitama, Japan.

We examined the effects of NIP-121, a potassium channel opener, on KCl- and norepinephrine (NE)-induced contraction, the phasic-contraction under the Ca(2+)-free condition and cytosolic free-Ca2+ mobilization using isolated rat aorta. NIP-121 as well as cromakalim inhibited, in the KCl- and NE-contractions concentration dependently. Glibenclamide, an ATP-sensitive potassium channel blocker, competitively reversed their inhibition. On the other hand, they did not inhibit the phasic-contractions induced by NE in Ca(2+)-free medium. In Fura-2-loaded rat aorta, NIP-121 inhibited only the late phase of the NE-induced cytosolic Ca2+ level ([Ca2+]cyt) increases that were inhibited by nicardipine. However, it did not inhibit the first [Ca2+]cyt increase, which was completely abolished by repeated applications of NE in Ca(2+)-free medium. Neither did it inhibit phorbol ester-induced contraction. The vasorelaxant mechanism of NIP-121 is attributable to the decrease in Ca2+ influx passing through the membrane Ca2+ permeable systems. In addition, inhibition of Ca2+ release from sarcoplasmic reticulum (SR) and of protein kinase C (PKC) activation may not be involved in vasorelaxation induced by NIP-121.

UI	MeSH Term	Description	Entries
D008297	Male		Males
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
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
D010069	Oxadiazoles	Compounds containing five-membered heteroaromatic rings containing two carbons, two nitrogens, and one oxygen atom which exist in various regioisomeric forms.	Oxadiazole
D010880	Piperidines	A family of hexahydropyridines.
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.
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
D004347	Drug Interactions	The action of a drug that may affect the activity, metabolism, or toxicity of another drug.	Drug Interaction,Interaction, Drug,Interactions, Drug
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia