Biomaterial Database

Influence of extracellular Na+ removal on cytosolic Ca2+ concentration in smooth muscle cells of rabbit cerebral artery. 1999

J K Kim, and S J Kim, and Y C Kim, and I So, and K W Kim

Department of Physiology & Biophysics, Seoul National University College of Medicine, Chongno-Gu, Korea.

There are some controversies over the contribution of Na+/Ca2+ exchanger (NCX) to the regulation of cytosolic Ca2+ concentration ([Ca2+]c) in smooth muscle. To prove the functional role of Na+/Ca2+ exchanger, we examined whether the removal of extracelluar Na+ could affect [Ca2+]c of rabbit cerebral arterial smooth muscle. The fluorescence ratio of fura-2 (R(340/380)) was measured in the single myocyte of rabbit middle cerebral artery and Na+ was substituted with the same concentration of NMDG+ or Li+. In 21 out of 230 cells tested, Na+ removal increased R(340,380) (deltaR(340/380)) by 115 +/- 16.5% of the deltaR(340/380) induced by 10 mM caffeine in the same cell. The Na+ removal-induced deltaR(340/380) was blocked by a selective inhibitor of cardiac type NCX exchanger (KB-R7943, (2-[2-[4-(4-nitrobenzyloxy)phenyl]ethyl]isothiourea, 10 microM). In those cells where the Na+ removal by itself did not increase R(340/380), the caffeine-induced deltaR(340/380) was increased by Na+-removal (130 +/- 9.8% of control response, n=30). Under the whole-cell patch clamp condition, short application of caffeine induced transient increase of outward current (I(K,Ca)-transient) which reflect the change of subsarcolemmal [Ca2+]. The application of KB-R7943 increased the amplitude of I(K,Ca)-transient (n=4). These results suggest the functional existence of NCX in rabbit cerebral artery smooth muscle.

UI	MeSH Term	Description	Entries
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
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
D002110	Caffeine	A methylxanthine naturally occurring in some beverages and also used as a pharmacological agent. Caffeine's most notable pharmacological effect is as a central nervous system stimulant, increasing alertness and producing agitation. It also relaxes SMOOTH MUSCLE, stimulates CARDIAC MUSCLE, stimulates DIURESIS, and appears to be useful in the treatment of some types of headache. Several cellular actions of caffeine have been observed, but it is not entirely clear how each contributes to its pharmacological profile. Among the most important are inhibition of cyclic nucleotide PHOSPHODIESTERASES, antagonism of ADENOSINE RECEPTORS, and modulation of intracellular calcium handling.	1,3,7-Trimethylxanthine,Caffedrine,Coffeinum N,Coffeinum Purrum,Dexitac,Durvitan,No Doz,Percoffedrinol N,Percutaféine,Quick-Pep,Vivarin,Quick Pep,QuickPep
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
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
D003600	Cytosol	Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.	Cytosols
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
D012964	Sodium	A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.	Sodium Ion Level,Sodium-23,Ion Level, Sodium,Level, Sodium Ion,Sodium 23
D013890	Thiourea	A photographic fixative used also in the manufacture of resins. According to the Fourth Annual Report on Carcinogens (NTP 85-002, 1985), this substance may reasonably be anticipated to be a carcinogen (Merck Index, 9th ed). Many of its derivatives are ANTITHYROID AGENTS and/or FREE RADICAL SCAVENGERS.
D015221	Potassium Channels	Cell membrane glycoproteins that are selectively permeable to potassium ions. At least eight major groups of K channels exist and they are made up of dozens of different subunits.	Ion Channels, Potassium,Ion Channel, Potassium,Potassium Channel,Potassium Ion Channels,Channel, Potassium,Channel, Potassium Ion,Channels, Potassium,Channels, Potassium Ion,Potassium Ion Channel