Biomaterial Database

Regulation of the plasma membrane Ca2+ pump by cyclic nucleotides in cultured vascular smooth muscle cells. 1988

K Furukawa, and Y Tawada, and M Shigekawa

Department of Molecular Physiology, National Cardiovascular Center Research Institute, Osaka, Japan.

We investigated the mechanisms of Ca2+ extrusion from cultured rat aortic smooth muscle cells while monitoring changes in the cytosolic Ca2+ concentration ([Ca2+]i) using fura 2 fluorescence. 45Ca2+ efflux from these cells consisted of two major mechanisms; one was dependent on the extracellular sodium concentration (Na+o) and the other was independent of Na+o. Na+o-dependent efflux increased monotonically with increasing [Ca2+]i between 0.1 and 1.0 microM, whereas Na+o-independent efflux reached a plateau at 0.6-1 microM [Ca2+]i with a half-maximum obtained at about 0.16 microM. At [Ca2+]i below 1 microM, the latter was significantly greater than the former. Unlike the Na+o-dependent mechanism, Na+o-independent 45Ca2+ efflux was inhibited almost entirely by extracellularly added La3+ or a combination of high extracellular pH (pH 8.8) and 20 mM Mg2+. It was also inhibited, although not completely, by compound 48/80, a calmodulin antagonist, and vanadate. These results strongly suggest that Na+o-dependent and Na+o-independent 45Ca2+ effluxes occur via the Na+/Ca2+ exchanger and the ATP-dependent Ca2+ pump, respectively. Sodium nitroprusside and atrial natriuretic factor, which are agents that stimulate intracellular production of cGMP, and 8-BrcGMP significantly accelerated the Na+o-independent 45Ca2+ efflux especially at low [Ca2+]i. Forskolin, dibutyryl cAMP, and 8-Br-cAMP, however, showed no stimulation. These results suggest that the plasma membrane Ca2+ pump is regulated by cGMP but not by cAMP in intact vascular smooth muscle cells.

UI	MeSH Term	Description	Entries
D007811	Lanthanum	The prototypical element in the rare earth family of metals. It has the atomic symbol La, atomic number 57, and atomic weight 138.91. Lanthanide ion is used in experimental biology as a calcium antagonist; lanthanum oxide improves the optical properties of glass.
D008274	Magnesium	A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
D008297	Male		Males
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
D009320	Atrial Natriuretic Factor	A potent natriuretic and vasodilatory peptide or mixture of different-sized low molecular weight PEPTIDES derived from a common precursor and secreted mainly by the HEART ATRIUM. All these peptides share a sequence of about 20 AMINO ACIDS.	ANF,ANP,Atrial Natriuretic Peptide,Atrial Natriuretic Peptides,Atriopeptins,Auriculin,Natriuretic Peptides, Atrial,ANF (1-126),ANF (1-28),ANF (99-126),ANF Precursors,ANP (1-126),ANP (1-28),ANP Prohormone (99-126),ANP-(99-126),Atrial Natriuretic Factor (1-126),Atrial Natriuretic Factor (1-28),Atrial Natriuretic Factor (99-126),Atrial Natriuretic Factor Precursors,Atrial Natriuretic Factor Prohormone,Atrial Natriuretic Peptide (1-126),Atrial Pronatriodilatin,Atriopeptigen,Atriopeptin (1-28),Atriopeptin (99-126),Atriopeptin 126,Atriopeptin Prohormone (1-126),Cardiodilatin (99-126),Cardiodilatin Precursor,Cardionatrin I,Cardionatrin IV,Prepro-ANP,Prepro-CDD-ANF,Prepro-Cardiodilatin-Atrial Natriuretic Factor,Pro-ANF,ProANF,Proatrial Natriuretic Factor,Pronatriodilatin,alpha ANP,alpha-ANP Dimer,alpha-Atrial Natriuretic Peptide,beta-ANP,beta-Atrial Natriuretic Peptide,gamma ANP (99-126),gamma-Atrial Natriuretic Peptide,Natriuretic Peptide, Atrial,Peptide, Atrial Natriuretic,Peptides, Atrial Natriuretic,Prepro ANP,Prepro CDD ANF,Prepro Cardiodilatin Atrial Natriuretic Factor,Pro ANF,alpha ANP Dimer,alpha Atrial Natriuretic Peptide,beta ANP,beta Atrial Natriuretic Peptide,gamma Atrial Natriuretic Peptide
D009599	Nitroprusside	A powerful vasodilator used in emergencies to lower blood pressure or to improve cardiac function. It is also an indicator for free sulfhydryl groups in proteins.	Nitroferricyanide,Sodium Nitroprusside,Cyanonitrosylferrate,Ketostix,Naniprus,Nipride,Nipruton,Nitriate,Nitropress,Nitroprussiat Fides,Nitroprusside, Disodium Salt,Nitroprusside, Disodium Salt, Dihydrate,Disodium Salt Nitroprusside,Nitroprusside, Sodium
D009712	Nucleotides, Cyclic		Cyclic Nucleotide,Cyclic Nucleotides,Nucleotide, Cyclic
D011921	Rats, Inbred WKY	A strain of Rattus norvegicus used as a normotensive control for the spontaneous hypertensive rats (SHR).	Rats, Wistar Kyoto,Wistar Kyoto Rat,Rats, WKY,Inbred WKY Rat,Inbred WKY Rats,Kyoto Rat, Wistar,Rat, Inbred WKY,Rat, WKY,Rat, Wistar Kyoto,WKY Rat,WKY Rat, Inbred,WKY Rats,WKY Rats, Inbred,Wistar Kyoto Rats
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
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes