Biomaterial Database

Actions of ATP and alpha, beta-methylene ATP on neuromuscular transmission and smooth muscle membrane of the rabbit and guinea-pig mesenteric arteries. 1985

S Ishikawa

In the rabbit mesenteric artery, adenosine triphosphate (ATP), showed two actions on the membrane potential of muscle cells: low concentrations (1-10 microM) hyperpolarized and high concentrations (greater than or equal to 50 microM) depolarized the membrane. Both changes in the potential were accompanied by increases in ionic conductance. In the rabbit mesenteric artery, alpha, beta-methylene ATP (MeATP), (greater than or equal to 30 nM) depolarized the muscle membrane at a lower concentration than ATP (greater than or equal to 50 microM), and increased the ionic conductance of the membrane. The depolarization induced by ATP was prevented by low concentrations of MeATP, but the hyperpolarization was retained. Furthermore, the hyperpolarization was not affected by theophylline (10 microM). In the guinea-pig mesenteric artery, ATP and MeATP depolarized and increased the ionic conductance of muscle membrane, but to depolarize the membrane, higher concentrations of both agents were required, compared to those in the rabbit mesenteric artery. In the mesenteric arteries from both species, perivascular nerve stimulation evoked excitatory junction potentials (e.j.ps). In both tissues, MeATP inhibited the amplitude of e.j.ps at lower concentrations than did ATP, and both agents had more potent inhibitory actions on rabbit than on guinea-pig. The inhibition of e.j.p. induced by low concentrations of these agents showed no relationship to depolarization, but the inhibition induced by high concentrations was paralleled by depolarization and increase in ionic conductance of the membrane. In the rabbit mesenteric artery, overflow of noradrenaline (NA) and its metabolite (3,4-dihydroxyphenylglycol; DOPEG) produced by perivascular nerve stimulation was examined. ATP (0.1 mM) but not MeATP (0.1 microM) reduced the overflow of NA, whereas both agents had no effect on the overflow of DOPEG. Exogenously applied high concentrations of NA (greater than or equal to 3 microM) depolarized the muscle membrane in both species. These NA-induced depolarizations were not affected by treatment with ATP or MeATP. It is concluded that, in the rabbit mesenteric artery, ATP is more likely to be involved in generation of e.j.ps than is NA. A similar interpretation in the guinea-pig mesenteric artery is complicated by the depolarization produced by high concentrations of ATP or MeATP.

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
D008638	Mesenteric Arteries	Arteries which arise from the abdominal aorta and distribute to most of the intestines.	Arteries, Mesenteric,Artery, Mesenteric,Mesenteric Artery
D008734	Methoxyhydroxyphenylglycol	Synthesized from endogenous epinephrine and norepinephrine in vivo. It is found in brain, blood, CSF, and urine, where its concentrations are used to measure catecholamine turnover.	Hydroxymethoxyphenylglycol,MHPG,MOPEG,Vanylglycol,4-Hydroxy-3-methoxyphenylethylene Glycol,4-Hydroxy-3-methoxyphenylethyleneglycol,4-Hydroxy-3-methoxyphenylglycol,Methoxyhydroxyphenylglycol, (+)-Isomer,Methoxyhydroxyphenylglycol, (+-)-Isomer,Methoxyhydroxyphenylglycol, (-)-Isomer,4 Hydroxy 3 methoxyphenylethylene Glycol,4 Hydroxy 3 methoxyphenylethyleneglycol,4 Hydroxy 3 methoxyphenylglycol
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
D009435	Synaptic Transmission	The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.	Neural Transmission,Neurotransmission,Transmission, Neural,Transmission, Synaptic
D009451	Neuroeffector Junction	The synapse between a neuron (presynaptic) and an effector cell other than another neuron (postsynaptic). Neuroeffector junctions include synapses onto muscles and onto secretory cells.	Junction, Neuroeffector,Junctions, Neuroeffector,Neuroeffector Junctions
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
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
D004558	Electric Stimulation	Use of electric potential or currents to elicit biological responses.	Stimulation, Electric,Electrical Stimulation,Electric Stimulations,Electrical Stimulations,Stimulation, Electrical,Stimulations, Electric,Stimulations, Electrical