OBJECTIVE Animal data suggest that the strong euphoriant effects of cocaine are related to the drug's enhancement of available dopamine at the synaptic cleft. The authors' goal was to determine whether this mechanism is the same in humans because the development of putative pharmacological agents for treatment of cocaine dependence depends on this knowledge. METHOD Positron emission tomograph...

• We have recently demonstrated that intravenous administration of the naturally occurring catecholamine, dopamine, increases effective renal plasma flow, glomerular filtration rate, and sodium excretion in normal human subjects. Since renal plasma flow increased in the absence of an alteration in mean arterial pressure, it was concluded that renal vascular resistance was decreased by dopamine....

Human glutathione transferase M2-2 prevents the formation of neurotoxic aminochrome and dopachrome by catalyzing the conjugation of dopamine and dopa o-quinone with glutathione. NMR analysis of dopamine and dopa o-quinone-glutathione conjugates revealed that the addition of glutathione was at C-5 to form 5-S-glutathionyl-dopamine and 5-S-glutathionyl-dopa, respectively. Both conjugates were fou...

CNS Spectr 13:4 April 2008 279 NEW TREND IN PSYCHOPHARMACOLOGY Dopamine (D)2 partial agonists (DPAs) activate D2 receptors in a manner that is less than the full agonist dopamine yet more than full antagonists (eg, most known antipsychotics). Various DPAs span the spectrum between full agonist at one end and antagonists at the other, with the antipsychotic aripiprazole close to the antagonist e...

Glutamate is the major excitatory neurotransmitter in central nervous system and, as such, many brain regions, including basal ganglia, are rich glutamatergic neurons. The importance of ganglia control voluntary movement has long been recognised, with effect dysfunction region exemplified by motor symptoms seen Parkinson’s disease (PD). However, and associated also play a role modulation emotio...

Exposure of tryptophan hydroxylase (TPH), the initial and rate-limiting enzyme in the biosynthesis of the neurotransmitter serotonin, to dopamine under mild oxidizing conditions (iron + H2O2) or in the presence of tyrosinase results in a concentration-dependent inactivation of the enzyme. Dopamine, iron, H2O2, or tyrosinase alone does not alter TPH activity. Similarly, N-acetyldopamine oxidized...

The antihypertensive effect of Padrenoreceptor-blocking agents may involve central mechanisms. Chronic propranolol treatment has been shown, for example, to increase total brain dopamine in experimental animals and centrally administered dopamine can lower blood pressure. This effect might be mediated by a direct reduction of sympathetic outflow but dopamine is known also to inhence anterior pi...

Synaptosomes are now known to possess a high degree. of metabolic independence during incubation in physiological medium, containing glucose as a substrate (see review by de Belleroche & Bradford, 1973). Under these conditions, depolarizing agents induce the calcium-dependent release of physiologically active compounds, including acetylcholine (de Belleroche &Bradford, 19726), aspartate, glutam...

A randomised, double blind, single dose study of topical haloperidol, a dopamine receptor blocking drug, was performed on 20 healthy volunteers. After its administration a modest reduction in intraocular pressure was recorded over the six-hour study period, but the difference was not significant at the p less than 0.05 level. Although dopamine blocking agents are effective in reducing intraocul...