Biomaterial Database

Electrical stimulation-induced alpha1- and alpha2-adrenoceptors-mediated contraction in isolated dog thoracic ducts. 1998

T Igarashi, and F Ikomi, and T Ohhashi

The 1st Department of Physiology, Shinshu University School of Medicine, Asahi, Matsumoto, Japan.

The electrical stimulation-induced responses of isolated dog thoracic ducts were investigated using an organ bath technique. Electrical stimulation (0.7 ms in pulse width, 25 V in nominal voltage, 10 s in duration time, 1-32 Hz at frequency) produced frequency-related contractions in the lymphatic preparations. The contractions were abolished by pretreatment with tetrodotoxin (10(-7) M), guanethidine (10(-7), 10(-6) M), and bretylium (10(-7), 10(-6) M). Cocaine (10(-6) M) significantly potentiated the electrical stimulation-induced contractions. Phentolamine (10(-8)-10(-5) M), prazosin (10(-8)-10(-5) M), bunazosin (10(-6), 10(-5) M), yohimbine (10(-8)-10(-6) M) and rauwolscine (10(-8)-10(-6) M) also dose-dependently reduced the contractions. On the other hand, propranolol (10(-8)-10(-6) M), atropine (10(-6) M), hexamethonium (10(-6) M), aspirin (3 x 10(-5) M), N(omega)-nitro-L-arginine methyl ester (L-NAME) (3 x 10(-5) M) and L-NAME (3 x 10(-5) M) + L-arginine (10(-4) M) caused no significant effect on electrical stimulation-induced contractions. No significant difference in the electrical stimulation-induced responses was observed between the lymphatic preparations with and without an intact endothelium. The electrical stimulation caused only a small contraction with no relaxation in the thoracic duct preparation precontracted with 10(-8) M U46619. The small contraction was abolished by 10(-5) M phentolamine. These findings suggest that there exists alpha1- and alpha2-adrenoceptors-mediated excitatory innervation, but no NO-ergic inhibitory nerve fiber in dog thoracic ducts.

UI	MeSH Term	Description	Entries
D008297	Male		Males
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
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
D009569	Nitric Oxide	A free radical gas produced endogenously by a variety of mammalian cells, synthesized from ARGININE by NITRIC OXIDE SYNTHASE. Nitric oxide is one of the ENDOTHELIUM-DEPENDENT RELAXING FACTORS released by the vascular endothelium and mediates VASODILATION. It also inhibits platelet aggregation, induces disaggregation of aggregated platelets, and inhibits platelet adhesion to the vascular endothelium. Nitric oxide activates cytosolic GUANYLATE CYCLASE and thus elevates intracellular levels of CYCLIC GMP.	Endogenous Nitrate Vasodilator,Mononitrogen Monoxide,Nitric Oxide, Endothelium-Derived,Nitrogen Monoxide,Endothelium-Derived Nitric Oxide,Monoxide, Mononitrogen,Monoxide, Nitrogen,Nitrate Vasodilator, Endogenous,Nitric Oxide, Endothelium Derived,Oxide, Nitric,Vasodilator, Endogenous Nitrate
D011930	Reaction Time	The time from the onset of a stimulus until a response is observed.	Response Latency,Response Speed,Response Time,Latency, Response,Reaction Times,Response Latencies,Response Times,Speed, Response,Speeds, Response
D011942	Receptors, Adrenergic, alpha	One of the two major pharmacological subdivisions of adrenergic receptors that were originally defined by the relative potencies of various adrenergic compounds. The alpha receptors were initially described as excitatory receptors that post-junctionally stimulate SMOOTH MUSCLE contraction. However, further analysis has revealed a more complex picture involving several alpha receptor subtypes and their involvement in feedback regulation.	Adrenergic alpha-Receptor,Adrenergic alpha-Receptors,Receptors, alpha-Adrenergic,alpha-Adrenergic Receptor,alpha-Adrenergic Receptors,Receptor, Adrenergic, alpha,Adrenergic alpha Receptor,Adrenergic alpha Receptors,Receptor, alpha-Adrenergic,Receptors, alpha Adrenergic,alpha Adrenergic Receptor,alpha Adrenergic Receptors,alpha-Receptor, Adrenergic,alpha-Receptors, Adrenergic
D004285	Dogs	The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)	Canis familiaris,Dog
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
D004730	Endothelium, Vascular	Single pavement layer of cells which line the luminal surface of the entire vascular system and regulate the transport of macromolecules and blood components.	Capillary Endothelium,Vascular Endothelium,Capillary Endotheliums,Endothelium, Capillary,Endotheliums, Capillary,Endotheliums, Vascular,Vascular Endotheliums
D004791	Enzyme Inhibitors	Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.	Enzyme Inhibitor,Inhibitor, Enzyme,Inhibitors, Enzyme