Biomaterial Database

P2-purinoceptor-mediated membrane currents in DDT1 MF-2 smooth muscle cells. 1989

A Molleman, and A Nelemans, and A Den Hertog

University of Groningen, Department of Pharmacology and Clinical Pharmacology, The Netherlands.

The electrophysiological response evoked by ATP was investigated in the DDT1 MF-2 smooth muscle cell line using the microelectrode technique and the whole-cell patch clamp technique. Application of ATP (10(-3) M) to the bathing solution caused a small initial depolarization of the cell membrane, followed by hyperpolarization and slow depolarization. During voltage clamping (-50 mV) a triphasic response was recorded on stimulation with ATP (10(-4)-10(-3) M). A short-lasting inward current was followed by a transient outward current and a slowly decreasing inward current. This response was not affected by the receptor antagonists, propranolol (3 X 10(-6) M), phentolamine (3 X 10(-6) M), atropine (3 X 10(-6) M) or theophylline (10(-3) M). The ATP-induced currents were not modified by the voltage-dependent channel blocking agents, tetraethyl ammonium (3 X 10(-3) M), 3,4-diaminopyridine (10(-3) M), tetrodotoxin (3 X 10(-7) M) or diltiazem (10(-5) M). The fast inward current was not detectable at a low ATP concentration (10(-5) M). The outward current showed a reversal potential near -76 mV, which equals the potassium equilibrium potential. This current was abolished after neutralization of the potassium electrochemical gradient. The outward current was suppressed under calcium-free conditions and also in the presence of tolbutamide (10(-4) M) or glipizide (5 X 10(-6) M). Guanosine triphosphate (5 X 10(-6) M) promoted the outward current, while this current was inhibited in the presence of guanosine diphosphate (5 X 10(-6) M).(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D007473	Ion Channels	Gated, ion-selective glycoproteins that traverse membranes. The stimulus for ION CHANNEL GATING can be due to a variety of stimuli such as LIGANDS, a TRANSMEMBRANE POTENTIAL DIFFERENCE, mechanical deformation or through INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS.	Membrane Channels,Ion Channel,Ionic Channel,Ionic Channels,Membrane Channel,Channel, Ion,Channel, Ionic,Channel, Membrane,Channels, Ion,Channels, Ionic,Channels, Membrane
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
D008839	Microelectrodes	Electrodes with an extremely small tip, used in a voltage clamp or other apparatus to stimulate or record bioelectric potentials of single cells intracellularly or extracellularly. (Dorland, 28th ed)	Electrodes, Miniaturized,Electrode, Miniaturized,Microelectrode,Miniaturized Electrode,Miniaturized Electrodes
D009130	Muscle, Smooth	Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)	Muscle, Involuntary,Smooth Muscle,Involuntary Muscle,Involuntary Muscles,Muscles, Involuntary,Muscles, Smooth,Smooth Muscles
D011983	Receptors, Purinergic	Cell surface proteins that bind PURINES with high affinity and trigger intracellular changes which influence the behavior of cells. The best characterized classes of purinergic receptors in mammals are the P1 receptors, which prefer ADENOSINE, and the P2 receptors, which prefer ATP or ADP.	Methyladenine Receptors,Purine Receptors,Purinergic Receptor,Purinergic Receptors,Purinoceptors,Purine Receptor,Purinoceptor,Receptors, Methyladenine,Receptors, Purine,Receptor, Purine,Receptor, Purinergic
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
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
D004563	Electrochemistry	The study of chemical changes resulting from electrical action and electrical activity resulting from chemical changes.	Electrochemistries
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.
D000255	Adenosine Triphosphate	An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.	ATP,Adenosine Triphosphate, Calcium Salt,Adenosine Triphosphate, Chromium Salt,Adenosine Triphosphate, Magnesium Salt,Adenosine Triphosphate, Manganese Salt,Adenylpyrophosphate,CaATP,CrATP,Manganese Adenosine Triphosphate,MgATP,MnATP,ATP-MgCl2,Adenosine Triphosphate, Chromium Ammonium Salt,Adenosine Triphosphate, Magnesium Chloride,Atriphos,Chromium Adenosine Triphosphate,Cr(H2O)4 ATP,Magnesium Adenosine Triphosphate,Striadyne,ATP MgCl2