Dopaminergic receptor sites

Photoaffinity Labeling of Striatal Dopaminergic Receptor Sites by Chlorpromaz ine... 

At high doses (R)-(92) selectively stimulated presynaptic dopaminergic receptor sites, whereas at lower doses it selectively stimulated postsynaptic receptor sites (59). In contrast, the ( S)-enantiomer stimulated presynaptic dopamine receptors and at the same dose level, it blocked postsynaptic dopamine recep-... 

McCallum SE, Parameswaran N, Bordia T, Fan H, McIntosh JM, Quik M (2006) Differential regulation of mesolimbic alpha 3/alpha 6 beta 2 and alpha 4 beta 2 nicotinic acetylchohne receptor sites, function after long-term oral nicotine to monkeys. J Pharmacol Exp Ther318 381-388 McKay BE, Placzek AN, Dani JA (2007) Regulation of synaptic transmission and plasticity by neuronal nicotinic acetylchohne receptors. Biochem Pharmacol 74 1120-1133 Mena-Segovia J, Winn P, Bolam JP (2008) Chohnergic modulation of midbrain dopaminergic systems. Brain Res Rev 58 265-271... 

A principal interest in our laboratory is the molecular characterization of CNS receptor sites of the neurotransmitter dopamine (DA, 5). These sites are strongly implicated in the biochemical etiology of schizophrenia and Parkinson s Disease, as well as other diseases of the CNS (50,51). Thus, the rank order of clinical potency of antipsychotic drugs (neuroleptics) correlates with the affinity of these drugs for dopaminergic sites (52,53), It is also well established that Parkinson s disease is directly related to deterioration in dopaminergic neurotransmission in the corpus striatum, which is a brain region rich in dopamine receptor sites (54). The use of L-DOPA, the biosynthetic precursor of dopamine, in treatment of patients with Parkinson s disease is one of the best examples of biochemically directed medical treatment. 

All the pharmacological and behavioural effects elicited by dopamine agonists and antagonists in the brain can only be explained if such an interaction occurs at the level of the dopamine receptor (D2 receptor site) the site still remains in search of a function. Bovine parathyroid cells were reported to possess dopamine sites which should be involved in the control of parathormone secretion. However, the very poor pharmacological characterization and the lack of in vivo evidence do not allow to assess the dopaminergic nature of this hormone secretion. Dopamine-sensitive adenylate cyclase is thus not a receptor directly implicated in the dopaminergic neurotransmission it is an enzyme which could have an important role in the control of long term metabolic effects such as the synthesis of neuronal constituents. 

---