Effects of dopaminoceptor agonists and antagonists on the rat vas deferens "in vitro". 1979

F M Tayo

Dopamine, noradrenaline, tyramine, amantadine and apomorphine produced concentration-related contractions of the rat vas deferens "in vitro". pD2 values of 5.35 +/- 0.12, 5.20 +/- 0.08, 4.50 +/- 0.06, and 4.50 +/- 0.10 were obtained for dopamine, noradrenaline, tyramine and apomorphine respectively. Phentolamine, haloperidol and pimozide blocked the effects of dopamine, tyramine, amantadine and apomorphine, however, noradrenaline-induced contractions were resistant to pimozide. Guanethidine (4 micrograms/ml) induced supersensitivity towards noradrenaline, almost abolished the effect of tyramine, but did not influence the effects of dopamine, amantadine and apomorphine at this concentration. These results confirm earlier reports that there are distinct dopaminoceptors in the rat vas deferens in addition to the conventional noradrenoceptors.

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
D010646 Phentolamine A nonselective alpha-adrenergic antagonist. It is used in the treatment of hypertension and hypertensive emergencies, pheochromocytoma, vasospasm of RAYNAUD DISEASE and frostbite, clonidine withdrawal syndrome, impotence, and peripheral vascular disease. Fentolamin,Phentolamine Mesilate,Phentolamine Mesylate,Phentolamine Methanesulfonate,Phentolamine Mono-hydrochloride,Regitine,Regityn,Rogitine,Z-Max,Mesilate, Phentolamine,Mesylate, Phentolamine,Methanesulfonate, Phentolamine,Mono-hydrochloride, Phentolamine,Phentolamine Mono hydrochloride
D011954 Receptors, Dopamine Cell-surface proteins that bind dopamine with high affinity and trigger intracellular changes influencing the behavior of cells. Dopamine Receptors,Dopamine Receptor,Receptor, Dopamine
D004298 Dopamine One of the catecholamine NEUROTRANSMITTERS in the brain. It is derived from TYROSINE and is the precursor to NOREPINEPHRINE and EPINEPHRINE. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. A family of receptors (RECEPTORS, DOPAMINE) mediate its action. Hydroxytyramine,3,4-Dihydroxyphenethylamine,4-(2-Aminoethyl)-1,2-benzenediol,Dopamine Hydrochloride,Intropin,3,4 Dihydroxyphenethylamine,Hydrochloride, Dopamine
D004305 Dose-Response Relationship, Drug The relationship between the dose of an administered drug and the response of the organism to the drug. Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
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
D006220 Haloperidol A phenyl-piperidinyl-butyrophenone that is used primarily to treat SCHIZOPHRENIA and other PSYCHOSES. It is also used in schizoaffective disorder, DELUSIONAL DISORDERS, ballism, and TOURETTE SYNDROME (a drug of choice) and occasionally as adjunctive therapy in INTELLECTUAL DISABILITY and the chorea of HUNTINGTON DISEASE. It is a potent antiemetic and is used in the treatment of intractable HICCUPS. (From AMA Drug Evaluations Annual, 1994, p279) Haldol
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
D014439 Tyramine An indirect sympathomimetic that occurs naturally in cheese and other foods. Tyramine does not directly activate adrenergic receptors, but it can serve as a substrate for adrenergic uptake systems and MONOAMINE OXIDASE to prolong the actions of adrenergic transmitters. It also provokes transmitter release from adrenergic terminals and may be a neurotransmitter in some invertebrate nervous systems. 4-(2-Aminoethyl)phenol,4-Hydroxyphenethylamine,p-Tyramine,para-Tyramine,4 Hydroxyphenethylamine

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