Biomaterial Database

Dissimilarity between the responses to adenosine triphosphate or its related compounds and non-adrenergic inhibitory nerve stimulation in the longitudinal smooth muscle of pig stomach. 1977

A Ohga, and T Taneike

1 Transmural electrical stimulation (TMS) of longitudinal smooth muscle strips taken from the cardiac portion of the pig stomach produced biphasic responses consisting of initial contractions followed by relaxations. The excitatory component was enhanced by neostigmine and abolished by atropine. After atropine treatment, TMS and nicotine or 1,1-dimethyl-4-phenyl-piperazinium, caused a relaxation or a relaxation followed by an after-contraction. All of these responses were abolished or reduced reversibly with tetrodotoxin and cocaine, while hexamethonium only abolished the response to ganglion-stimulating agents.2 The relaxation caused by TMS reached a maximum amplitude at 5-10 Hz, and was entirely resistant to the effects of alpha- and beta-adrenoceptor blocking agents, or a combination of them, and also to guanethidine. These results strongly suggested that the relaxation was elicited by stimulation of intramural non-adrenergic inhibitory neurones.3 In the presence of atropine and guanethidine, adenosine triphosphate (ATP, 5-20 muM) caused only a tonic contraction, and ATP (25-200 muM) or adenosine diphosphate (25-200 muM) produced a contractile response or a biphasic one (tonic contraction preceded by a slight relaxation). Adenosine monophosphate and adenosine caused only the tonic contraction over the range of concentrations (25-200 muM).4 Stimulation of the intramural inhibitory neurones of the tissue consistently evoked an inhibitory junction potential, which showed a summation during repetitive stimulation. One the other hand, ATP elicited mainly a small depolarization of a few mV.5 When the desensitization to ATP of the muscle was achieved in the presence of atropine and guanethidine, the relaxation induced by stimulation of the non-adrenergic inhibitory neurones could be evoked without any modification.6 Dipyridamole neither potentiated the inhibitory responses due to stimulation of the intramural inhibitory neurones nor showed any consistent effect on the ATP-induced response.7 From these results, it is unlikely that ATP, or any related compound, is the transmitter substance of the intramural inhibitory neurones in the longitudinal smooth muscle of the pig stomach.

UI	MeSH Term	Description	Entries
D008297	Male		Males
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
D009433	Neural Inhibition	The function of opposing or restraining the excitation of neurons or their target excitable cells.	Inhibition, Neural
D004176	Dipyridamole	A phosphodiesterase inhibitor that blocks uptake and metabolism of adenosine by erythrocytes and vascular endothelial cells. Dipyridamole also potentiates the antiaggregating action of prostacyclin. (From AMA Drug Evaluations Annual, 1994, p752)	Antistenocardin,Apo-Dipyridamole,Cerebrovase,Cléridium,Curantil,Curantyl,Dipyramidole,Kurantil,Miosen,Novo-Dipiradol,Persantin,Persantine,Apo Dipyridamole,Novo Dipiradol
D004347	Drug Interactions	The action of a drug that may affect the activity, metabolism, or toxicity of another drug.	Drug Interaction,Interaction, Drug,Interactions, Drug
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
D005260	Female		Females
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
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
D013270	Stomach	An organ of digestion situated in the left upper quadrant of the abdomen between the termination of the ESOPHAGUS and the beginning of the DUODENUM.	Stomachs