Dopamine receptors previously identified in corpora allata (CA) of Manduca sexta last instars on the basis of dopamine effects on JH (juvenile hormone)/JH acid biosynthesis and cyclic AMP (cAMP) accumulation, were characterized pharmacologically. For this study, a broad spectrum of agonists or antagonists of D1, D2, D3 or D4 dopamine receptors, together with the dopamine metabolite N-acetyl-dop...

The dopamine D(1), D(2), D(3) receptors, vesicular monoamine transporter type-2 (VMAT2), and dopamine transporter (DAT) densities were measured in 11 aged human brains (aged 77-107.8, mean: 91 years) by quantitative autoradiography. The density of D(1) receptors, VMAT2, and DAT was measured using [(3)H]SCH23390, [(3)H]dihydrotetrabenazine, and [(3)H]WIN35428, respectively. The density of D(2) a...

G protein-coupled dopamine receptors (D1, D2, D3, D4, and D5) mediate all of the physiological functions of the catecholaminergic neurotransmitter dopamine, ranging from voluntary movement and reward to hormonal regulation and hypertension. Pharmacological agents targeting dopaminergic neurotransmission have been clinically used in the management of several neurological and psychiatric disorder...

The possible interaction of melatonin receptors and D1 dopamine receptors was investigated in neural cells prepared from embryonic day 8 chick retinas and cultured for 6 d. Dopamine stimulated cAMP accumulation in cultured retinal cells. This effect of dopamine was antagonized by addition of dopamine receptor antagonists (haloperidol and SCH23390) or melatonin receptor agonists (melatonin, 2-io...

Tetanic stimuli to layer I-II afferents in rat prefrontal cortex induced long-term depression (LTD) of layer I-II to layer V pyramidal neuron glutamatergic synapses when tetani were coupled to bath application of dopamine. This LTD was blocked by the following metabotropic glutamate receptor (mGluR) antagonists coapplied with dopamine: (S)-alpha-methyl-4-carboxyphenylglycine (MCPG; group I and ...

Dopamine is monoamine neurotransmitter. Dopamine is produced in the dopaminergic neurons in the ventral tegmental area of the substantia nigra, midbrain and the arcuate nucleus of the hypothalamus. In the periphery, dopamine is found in the kidney where it functions to produce renal vasodilation, diuresis, and natriuresis. Dopamine neurons are more widely distributed than those of other monamin...

The prokinetic effect of metoclopramide is mediated through the blockade of enteric (neuronal and muscular) inhibitory dopamine D2 receptors, and metoclopramide has the ability to stimulate 5-HT3 and 5-HT4 receptors (2). Metoclopramide also exerts inhibitory effects on D2 receptors centrally (located outside the blood-brain barrier), and these contribute to its antiemetic effect. Metoclopramide...

The medial entorhinal cortex (MEC) receives a dense dopaminergic innervation and expresses dopamine receptors. However, little is known about the effect of dopamine on GABAergic transmission in this region of the brain. In this study, we recorded GABAA receptor-mediated spontaneous inhibitory postsynaptic currents (sIPSCs) and miniature inhibitory postsynaptic currents (mIPSCs) by using whole-c...

intraperitoneal (ip) injection of bupropion (3,6, amine (4,16 mg kg•&apos;) induced dose-dependent climbing in mice. the climbing response induced by both drugs were decreased in animals pretreated either with the 0-1 antagonist sch 233<)0 or the 0-2 antagonist sulpiride. the α-adrenoceptor blocker phenoxybenzamine decreased the climbing induced by both bupropion and amphetamine, but the β-adre...

BACKGROUND Depletion of central nervous system catecholamines, including dopamine, can decrease MAC (the minimum alveolar concentration of an inhaled anesthetic required to suppress movement in response to a noxious stimulus in 50% of test subjects); release of central nervous system catecholamines, including dopamine, can increase MAC; and increased free dopamine concentrations in the striatum...