Top Research Papers on Dopamine

The results show that dopexamine exerts systemic and renal effects mainly via stimulation of beta 2-receptors, while renal vascular resistance and systemic vascular resistance declined to almost the same extent.

The present study revealed that neither substance is superior in the treatment of cardiogenic shock, even if the effect on myocardial consumption and the reported beneficial effects on renal and splanchnic functions might favour the use of dopexamine under certain circumstances.

Conformationally restricted analogs of dopamine--namely, the cis and trans 2-amino-1(3,4-dihydroxyphenyl)cyclobutane hydrochlorides--were tested for their affinity to the receptor, and the trans-restricted analogs had more affinity for the receptor site, indicating that dopamine probably interacts with the receptor in the trans conformation.

A small dose is started at bedtime, after a patient is unlikely to purge, and the dosage should be gradually raised over the next few days to a therapeutic range, so that most patients have at least some symptomatic improvement.

Dopastin has been synthesised from L-valinol by an 8-step procedure, in which the key stage involves oxaziran formation followed by hydrolysis with Dowex 50W, with retention of the absolute configuration of the starting material in the final product.

The most common off-targets for established dopamine receptor ligands are given and an outline of molecules sufficiently specific for one or more subtypes, the presence of DR, α2-ARs, and 5-HT receptors in CNS areas, which could help avoid ambiguous results.

Direct evidence that neuroleptics selectively blocked dopamine receptors occurred in 1974 with the finding that nanomolar concentrations of these drugs stereoselectively inhibited the binding of [3H]‐dopamine or [3h]‐haloperidol.

Research efforts in the area of peripheral dopamine have now established the presence of two distinct subtypes--DA1 and DA2--of DA receptors, and have identified a potential role for dopamine produced within the kidney in the control of renal sodium excretion.

An association of Adult Attention Deficit Hyperactivity Disorder With Dopamine Transporter Gene,Dopamine D3 Receptor, and Dopamines D4 Receptor Gene Polymorphisms is described.

A series of studies that have shown unique properties of dopamine neurons projecting to the posterior "tail" of the striatum (TS) in terms of anatomy, activity, and function indicate that there are at least two axes of dopamine-mediated reinforcement learning in the brain.

The novel DA1 receptor agonist fenoldopam is claiming a role in the management of hypertension, heart failure, and the preservation of renal function, and DA2 receptor agonists are also being evaluated as potential antihypertensive agents.

The main aim of this paper is to review the different pathways of dopamine and its agonists in prolactinomas to help to gain a better understanding of their functions and drug resistance mechanisms.

D dopamine release occurs also at the somatodendritic level, providing a substrate for an ultrashort autoregulatory feedback loop and shedding light on a long-standing controversy about the existence of neuroendocrine transmitter reuptake.

The author suggests that biochemical labeling of the dopamine receptor with 3H-dopamine and3H-haloperidol may clarify mechanisms of drug effects on the dopamine receptors.

In postmortem samples of caudate nucleus and nucleus accumbens from 48 schizophrenic patients, there were significant increases in both the maximum number of binding sites (Bmax) and the apparent dissociation constant (KD) for tritiated spiperone.

Because D2 receptors in striatum are mainly localized in gamma-aminobutyric acid (GABA) cells these results provide evidence of GABAergic involvement in the dopaminergic abnormalities seen in alcoholics.

The dopamine receptor and its function will be of value not only in pathophysiological studies of human pituitary adenomas, but also in the development of new pharmacological agents to treat patients with these tumours.

A dopamine (DA) polymer was deposited electrochemically on to a glassy carbon (GC) surface until the electrode surface was passivated. The DA film on the GC surface was re-formed for high sensitivity and reproducibility by electrochemical degradation. The re-formed electrode was sensitive and selective in the determination of DA in the presence of ascorbic acid. The linear range obtained by square-wave voltammetry was between 0.1 and 2.1 μM (R=0.996, n=6) with a sensitivity of 1.2 μA μM−1 and a detection limit (S/N=3) of 0.04 μM. The electropolymerized DA film was stable and the re-formed elec...

Evidence for using inotropic agents such as dopexamine, dobutamine, and dopamine in patients with sepsis, postoperative trauma, and in those undergoing cardiac surgery and mechanical ventilation to increase gut perfusion and prevent multiple organ failure is examined.

The results suggest that the effects of PD 128907 on dopamine cell function reflect stimulation of D2 as opposed to D3 receptors, which may participate in postsynaptically activated short-loop feedback modulation of DA release.

It is found that mice homozygous for this ASD-associated mutation display impaired striatal DA neurotransmission and altered DA-dependent behaviors that correspond with some of the behavioral phenotypes observed in ASD.

The data suggest that the hypothermia observed in DATk mice may be mediated through D3 receptors, and inactivation of the D3R gene resulted in significant hyperactivity and further elevation of striatal extracellular dopamine above levels observed in respective single mutant mice.

D dopamine plays a main role in the reward system with regard to obesity, and the association of DR availability with BMI was dependent on radiopharmaceuticals, while DAT availability did not show the significant relationship with BMI regardless of radiophARMaceuticals.

The agedependent distribution and some functional aspects of several parts of the renal dopamine system (dopamine, AADC, COMT, D1 receptor, and DARPP-32) during renal morphogenesis are discussed.

Findings implicate DBH in the genetics of MA and are consistent with low NE and increased DA activities in migraine.

This chapter discusses the D2-Like Dopamine Autoreceptor and its role in the Dopaminergic System, as well as some of the mechanisms behind its recognition and action.

If ten years ago the use of natural dopamine receptors on cell membranes seemed impossible for biosensors, the actual technology allows co-integrate transistors and vesicles with natural receptors of dopamine, like G protein-coupled receptors, and the uni-molecular detection selectivity is promising.

Psychosis is one of the psychiatric disorders that is controlled by dopaminergic drugs such as antipsychotics that have affinity for the dopamine D2 receptor (DRD2). In this investigation we perform quantum chemical calculations of two molecules [dopamine and risperidone] within a large cavity of DRD2 that represents the binding site of the receptor. Dopamine is an endogenous neurotransmitter and risperidone is a second-generation antipsychotic. Non-covalent interactions of dopamine and risperidone with DRD2 are analyzed using the Quantum Theory of Atoms in Molecules (QTAIM) and the Non-Covale...

J. Neurochem. (2011) 118, 475–489.

During brief dopamine treatment of endotoxic shock in rats, neither dopamine nor cysteinyl-dopamine crossed the blood-brain barrier, suggesting a significant fraction of exogenously administered dopamine reacts with -SH groups of cysteine and probably also with --SH groups on peptides and proteins.

Rapid perfusion flow rates eliminate DA reuptake and DA uptake inhibitors either with or without DA releasing capabilities block the release of DA induced by μM levels of external DA.

The results establish not only the central importance of the transporter as the key element controlling dopamine levels in the brain, but also its role as an obligatory target for the behavioral and biochemical action of amphetamine and cocaine.

It was in this country, and in great measure here in London, that this at first inconspicuouslooking substance entered the stage of biological research, and the possibility that dopamine has some functions of its own which are not yet known is shown.

D2R signaling was involved in the genotoxicity of dopamine by affecting activation and cell surface expression of DAT and hence modulating dopamine uptake, and dopamine exerted its genot toxicity in vitro upon transport into the cells and oxidation by MAO.

In vitro studies on an intact gastroduodenal preparation of the guinea-pig indicated that dopamine inhibited motor activity via a direct action on the gastrointestinal wall and in vivo on conscious dogs confirmed the presence of dopamine receptors in the stomach of conscious dogs.

This is the first report of a functional role for D3 receptors and establishes these cell lines as a convenient in vitro model system to study signal transduction mechanisms associated with autoreceptor function.

The data suggest that spiperone‐reversible inhibition of locomotion in mice is a good criterion for dopamine autoreceptor agonists and a separate mechanism for inhibiting dopamine release is probably involved.

Levodopa and dopamine were toxic to D8 cells and dopamine binding sites and the function of DAT was improved after the use of levodopa at an optimal dosage.

Dopamine analogues are synthesized in which the nitrogen atom is replaced with aneutral methyl sulfide, a neutral methyl selenides, a charged dimethylsulfonium iodide, and a charged Dimethylselenonium iodine to gain insight as to which species is better suited for interaction with the dopamine receptor.

A D2R cellular model is developed using a single cell line background to assess the activation of different signaling pathways downstream of the D1R and new examples of previously unappreciated functionally selective ligands are discovered.

This review is concerned primarily with similari­ ties and differences in the effects of agonists and antagonists acting on the DA receptor in the canine renal vascular bed and on selected DA receptors described in other organs and species.

Methods for measuring dopamine release HPLC with electrochemical detection and catechol structure imparts critical properties related to the interactions between dopamine and its receptors, but also reduces the chemical stability of molecules bearing it.

The results suggest that the chronic presence of dopaminergic neurotransmission is required to dampen the intracellular signaling response of striatal neurons.

The results cannot be explained by an interaction with alpha- receptors, since alpha-adrenergic blocking concentrations of prazosin were inactive against dopamine, and dopamine-blocking concentrations of domperidone did not interfere with noradrenaline-induced relaxations.

The ongoing and future work on the precise role of DA in schizophrenia should focus on first-episode/admission neuroleptic-naive schizophrenic patients, as such studies represent the best opportunity of finding out specific changes in the dopaminergic pathways and relating them in a meaningful way to various dimensions of psychopathology seen in schizophrenia patients.

Dopamine has been marketed for several years in the USA and is now available here for the treatment of shock ‘associated with myocardial infarction, trauma, endotoxic septicaemia, open-heart surgery, renal failure and chronic cardiac decompensation as in congestive failure’.

The disadvantages of dopamine agonists as compared with levodopa therapy are outlined and the features and costs of the four Food and Drug Administration-approved agonists and apomorphine are discussed.

It was found that lungs that were topically cooled for 6 hours in non-heart-beating donor pigs were suitable for transplantation and dopamine excerts principally much the same effects at 32oC as in normothermia, however, dopamine may compromize ventricular filling in hypothermia due to it`s chronotropic effect combined with a hypotheria-induced shortening of diastolic filling time.

Introverts were found to be much more susceptible to pharmacologically induced changes in D2 receptor activity than extraverts, providing additional experimental evidence for the notion that individual differences in D 2 receptor responsivity may represent a neurobiological substratum for the personality dimension of extraversion.

The fMRI study by Carter et al. (2009) offers an important insight into the role of dopamine signals in human decision making and has raised a possibility that distinct populations of dopamine neurons might be involved in representing salience and valence separately.