Their activation results in inhibition of norepinephrine release. Peripheral DA2 receptors are found presynaptically on adrenergic nerve terminals and in sympathetic ganglia. Shepherd, in Hypertension, 2007 PERIPHERAL DOPAMINE-2 RECEPTOR AGONISTS A high proportion of patients of non-Caucasian ethnicity have been identified, suggestive of some genetic susceptibility.Īlexander M.M. Patients may be immunotherapy responsive, but relapses are noted in 25% of this rare cohort. Patients' antibodies bind to two main regions of the extracellular N-terminus of D2R (amino acids 20–29 and 23–37), with glycosylation-independent epitope recognition at N23 ( Sinmaz et al., 2016). MRI may reveal basal ganglia swelling and hyperintensity, which on follow up may present as basal ganglia atrophy and gliosis ( Dale et al., 2012). CSF may demonstrate lymphocytic pleocytosis and/or oligoclonal bands. Indeed, children with D2R antibodies develop a “basal ganglia encephalitis” phenotype with prominent movement disorders including parkinsonism, dystonia, and/or chorea in addition to hypersomnolence, and neuropsychiatric features like obsessive-compulsive disorder, psychosis, and emotional lability ( Dale et al., 2012). Irani, in Reference Module in Neuroscience and Biobehavioral Psychology, 2018 Dopamine 2 Receptor (D2R)ĭ2R is a postsynaptic receptor which is highly expressed in the striatum, and plays an important role in dopaminergic neurotransmission and in the circuitry intimately involved in motor control.
Further research into targeting the dopamine pathway as a possible treatment is necessary given the high positivity of dopamine D2 receptor expression in meningiomas. Recently, cabergoline (D2 receptor predominant agonist) treatment of a patient with recurrent meningioma demonstrated a good response with no compressive symptoms or tumor size increase 11 years after treatment ( Castelo-Branco et al., 2011). Dopamine D2 receptor expression was positive in 93.6% of the cases, but there were not significant expression differences in tumor recurrence, regrowth status, or tumor grade.Īt micromolar concentrations, dopamine and its agonists bromocriptine (D2 receptor predominant), SKF-38393 (D1 agonist), and apomorphine (D1 and D2) show a significant decrease in meningioma cell proliferation rate in culture ( Trott et al., 2015). Immunohistochemical staining for dopamine 2 (D2) receptor in tumor tissue from 157 patients with meningioma who underwent surgical resection was performed in 141 grade I, 13 grade II, and 3 grade III meningioma tumors ( Trott et al., 2015). Interestingly, antiproliferative effects have been associated with this activation. Randy Jensen, in Handbook of Clinical Neurology, 2020 Dopamineĭopamine D2 receptor activation induces pathways involved in cell differentiation, growth, metabolism, and apoptosis, especially the ERK and/or MAPK pathways.
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