Biomaterial Database

Vagal non-adrenergic inhibition of guinea-pig stomach. 1971

L Beani, and C Bianchi, and A Crema

1. The effect of vagal and sympathetic stimulation on the mechanical and electrical activity (intracellular recording) of the body of the guinea-pig stomach was investigated in vitro.2. Following atropine, 1 x 10(-6)-1 x 10(-7) g/ml., vagal responses were reversed from excitatory to inhibitory.3. Sympathetic blockade, produced by alpha- and beta-receptor antagonists and adrenergic neurone-blocking agents, reduced or abolished sympathetic, but not vagal inhibition.4. Hexamethonium (5 x 10(-5) g/ml.) reduced vagal relaxation to 11-30% according to the stimulation rate. The residual response was maintained in the presence of 5-hydroxytryptamine tachyphylaxis.5. Many muscle cells were observed to be under the influence of both vagus and sympathetic nerves: the effect of sympathetic stimulation was always inhibitory in nature, but high stimulation rates were required. The effect of vagal stimulation was both excitatory and inhibitory even in the absence of atropine: low stimulation rates gave rise either to E.J.P.s (excitatory junctional potentials), often followed by spikes, or to I.J.P.s (inhibitory junctional potentials).6. In some spontaneously firing cells the interruption of electrical activity produced by vagal stimulation at 2/sec and sympathetic stimulation at 20/sec was recorded for a long enough time to check the effect of guanethedine (5 x 10(-6) g/ml.): the drug selectively blocked sympathetic inhibition.7. The significance of the inhibitory non-adrenergic transmitter, released by the intramural neurones activated by preganglionic vagal fibres, is discussed.

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
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
D009132	Muscles	Contractile tissue that produces movement in animals.	Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, Muscle
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
D009474	Neurons	The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.	Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
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
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.
D005260	Female		Females
D006145	Guanethidine	An antihypertensive agent that acts by inhibiting selectively transmission in post-ganglionic adrenergic nerves. It is believed to act mainly by preventing the release of norepinephrine at nerve endings and causes depletion of norepinephrine in peripheral sympathetic nerve terminals as well as in tissues.	((2-Hexahydro-1(2H)-azocinyl)ethyl)guanidine,Guanethidine Monosulfate,Guanethidine Sulfate,Guanethidine Sulfate (1:1),Guanethidine Sulfate (1:2),Guanethidine Sulfate (2:1),Guanethidine Sulfate (2:1), 14C-Labeled,Ismelin,Isobarin,Octadine,Oktadin,Monosulfate, Guanethidine,Sulfate, Guanethidine