Biomaterial Database

Inhibition by dopamine of the neurotransmission in the rat vas deferens. 1986

A M Dopico, and M L Fiszman, and F J Stefano

The effects of alpha-adrenoceptor and dopaminoceptor agonists and antagonists were investigated on presynaptic receptors in the prostatic portion of rat vas deferens. The variable studied was the early component (250 msec) of the motor response elicited by field stimulation (single pulses). All the experiments were carried out in the presence of cocaine 30 mumol/l and hydrocortisone 28 mumol/l so as to block the sites of amines loss and 1-propranolol 0.3 mumol/l to block beta-adrenoceptors. Clonidine, noradrenaline (NA) and dopamine (DA) inhibited the motor response in a concentration-dependent manner. DA was 10 and 10(4) times less potent than NA and clonidine respectively. The selective D2 agonist, LY 141865, failed to inhibit the motor response even at a high concentration (30 mumol/l). Yohimbine (0.1, 0.3 and 1 mumol/l) antagonized competitively the effect of clonidine, NA and DA showing similar - log KB values (7.57; 7.68 and 7.09 respectively). Likewise, idaxozan (0.03 mumol/l) blocked the inhibitory effect of DA in the same order of potency (- log KB = 7.81). On the other hand, pimozide 0.21 mumol/l and Schering 23390 3 mumol/l antagonized the inhibitory effect of DA, showing a lower potency than the other antagonists. Taken together, these findings do not support the hypothesis that DA activates a specific population of prejunctional dopaminoceptors to inhibit the motor response elicited by field stimulation in the presence of cocaine, hydrocortisone and 1-propranolol in the prostatic portion of the rat vas deferens. Instead, the population of prejunctional alpha 2-adrenoceptor may be involved.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009046	Motor Neurons	Neurons which activate MUSCLE CELLS.	Neurons, Motor,Alpha Motorneurons,Motoneurons,Motor Neurons, Alpha,Neurons, Alpha Motor,Alpha Motor Neuron,Alpha Motor Neurons,Alpha Motorneuron,Motoneuron,Motor Neuron,Motor Neuron, Alpha,Motorneuron, Alpha,Motorneurons, Alpha,Neuron, Alpha Motor,Neuron, Motor
D009431	Neural Conduction	The propagation of the NERVE IMPULSE along the nerve away from the site of an excitation stimulus.	Nerve Conduction,Conduction, Nerve,Conduction, Neural,Conductions, Nerve,Conductions, Neural,Nerve Conductions,Neural Conductions
D011919	Rats, Inbred Strains	Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.	August Rats,Inbred Rat Strains,Inbred Strain of Rat,Inbred Strain of Rats,Inbred Strains of Rats,Rat, Inbred Strain,August Rat,Inbred Rat Strain,Inbred Strain Rat,Inbred Strain Rats,Inbred Strains Rat,Inbred Strains Rats,Rat Inbred Strain,Rat Inbred Strains,Rat Strain, Inbred,Rat Strains, Inbred,Rat, August,Rat, Inbred Strains,Rats Inbred Strain,Rats Inbred Strains,Rats, August,Rats, Inbred Strain,Strain Rat, Inbred,Strain Rats, Inbred,Strain, Inbred Rat,Strains, Inbred Rat
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
D003000	Clonidine	An imidazoline sympatholytic agent that stimulates ALPHA-2 ADRENERGIC RECEPTORS and central IMIDAZOLINE RECEPTORS. It is commonly used in the management of HYPERTENSION.	Catapres,Catapresan,Catapressan,Chlophazolin,Clofelin,Clofenil,Clonidine Dihydrochloride,Clonidine Hydrochloride,Clonidine Monohydrobromide,Clonidine Monohydrochloride,Clopheline,Dixarit,Gemiton,Hemiton,Isoglaucon,Klofelin,Klofenil,M-5041T,ST-155,Dihydrochloride, Clonidine,Hydrochloride, Clonidine,M 5041T,M5041T,Monohydrobromide, Clonidine,Monohydrochloride, Clonidine,ST 155,ST155
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
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
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
D012964	Sodium	A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.	Sodium Ion Level,Sodium-23,Ion Level, Sodium,Level, Sodium Ion,Sodium 23