scholarly journals Effect of Zishenpingchan Granule on Neurobehavioral Manifestations and the Activity and Gene Expression of Striatal Dopamine D1 and D2 Receptors of Rats with Levodopa-Induced Dyskinesias

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Qing Ye ◽  
Xiao-Lei Yuan ◽  
Jie Zhou ◽  
Can-xing Yuan ◽  
Xu-ming Yang

This study was performed to observe the effects of Zishenpingchan granule on neurobehavioral manifestations and the activity and gene expression of striatal dopamine D1 and D2 receptors of rats with levodopa-induced dyskinesias (LID). We established normal control group, LID model group, and TCM intervention group. Each group received treatment for 4 weeks. Artificial neural network (ANN) was applied to excavate the main factor influencing variation in neurobehavioral manifestations of rats with LID. The results showed that overactivation in direct pathway mediated by dopamine D1 receptor and overinhibition in indirect pathway mediated by dopamine D2 receptor may be the main mechanism of LID. TCM increased the efficacy time of LD to ameliorate LID symptoms effectively mainly by upregulating dopamine D2 receptor gene expression.

2020 ◽  
Vol 13 ◽  
Author(s):  
Ritesh Daya ◽  
Joella Ho ◽  
Sharon Thomson ◽  
Jayant Bhandari ◽  
Ram K. Mishra

Background: Allosteric modulators of G-protein coupled receptors regulate receptor activity by binding to sites other than the active site and have emerged as a new and highly desirable class of drugs. PAOPA (3(R)-[(2(S)- pyrrolidinylcarbonyl)amino]-2-oxo-1-pyrrolidineacetamide), a peptidomimetic analog of Prolyl-Leucyl-Glycinamide, is a potent dopamine D2 receptor allosteric modulator. PAOPA has shown therapeutic effects in pre-clinical models of schizophrenia and extrapyramidal dysfunction. Objective: in this study, we sought to examine the biomolecular underpinnings of PAOPA‘s therapeutic outcomes in preclinical models of schizophrenia. Method: Following sub-chronic (daily for 7 days) administration of PAOPA, we assessed levels of dopamine D2 receptors, receptor kinases (GRK2 (G protein-coupled receptor kinase 2) and Arrestin-3), and phosphorylated mitogenactivated protein kinase (MAPKs), namely, extracellular signal-regulated kinases (ERK1/2) in the hippocampus, medial pre-frontal cortex, nucleus accumbens, pre-frontal cortex, and dorsal striatum via protein quantification. Results: Following 7 days of daily PAOPA treatment, we observed decreased GRK2 and increased dopamine D2 receptor expression in the dorsal striatum. These findings potentially underscore PAOPA’s therapeutic mechanism of action for the positive-like symptoms of schizophrenia in pre-clinical animal models. Additionally, we observed a decline in GRK2 in the hippocampus and an increase in phosphorylated ERK1 in the pre-frontal cortex, suggestive of a role for PAOPA in treating cognitive and/or affective dysfunction in pre-clinical models. Conclusion: While further studies are required to elucidate PAOPA’s mechanism of action, this study builds on prior investigations and develops an early framework to describe the therapeutic mechanism of action of PAOPA.


2011 ◽  
Vol 26 (4) ◽  
pp. 564-574 ◽  
Author(s):  
Maryam Bananej ◽  
Ahmad Karimi-Sori ◽  
Mohammad Reza Zarrindast ◽  
Shamseddin Ahmadi

Involvement of the dopamine receptors in the basolateral amygdala (BLA) in the effects of histamine on anxiety-like behaviors of the elevated plus maze in male Wistar rats was investigated. The results showed that bilateral intra-BLA injections of histamine (2.5, 5 and 7.5 µg/rat) induced an anxiogenic-like effect, revealed by decreases in percentage of open arm time (%OAT) and open arm entries (%OAE). Intra-BLA administration of dopamine D1 receptor agonist, SKF38393 (0.25 µg/rat), and dopamine D2 receptor agonist, quinpirole (0.03 and 0.05 µg/rat), decreased %OAT but not %OAE. Conversely, intra-BLA administration of dopamine D1 receptor antagonist, SCH23390 (0.5 and 1 µg/rat), and dopamine D2 receptor antagonist, sulpiride (0.3 and 0.5 µg/rat), increased %OAT and %OAE, suggesting an anxiolytic-like effect for both drugs. Interestingly, co-administration of a silent dose of SCH23390 or sulpiride prevented anxiogenic-like effects of SKF38393 and quinpirole, respectively. Conjoint administration of a sub-effective dose of SKF38393 (0.125 µg/rat) or quinpirole (0.01 µg/rat) along with lower doses of histamine (1 and 2.5 µg/rat) induced anxiolytic-like effects. On the other hand, intra-BLA pretreatment with a silent dose of SCH23390 (0.25 µg/rat) or sulpiride (0.1 µg/rat) prevented the anxiogenic-like effect of higher doses of histamine (5 and 7.5 µg/rat). No significant change was observed in total closed arm entries, as an index for motor activity of the animals. It can be concluded that the dopamine D1 and D2 receptors in the BLA may be involved in the anxiogenic-like effects induced by histamine.


Cephalalgia ◽  
1994 ◽  
Vol 14 (3) ◽  
pp. 235-240 ◽  
Author(s):  
C Wöber ◽  
T Brücke ◽  
C Wöber-Bingöl ◽  
S Asenbaum ◽  
P Wessely ◽  
...  

We studied in vivo the influence of flunarizine on dopamine D2 receptors and investigated whether dopamine D2 receptor blockade is involved in its antimigraine action. Eleven migraine patients, treated with flunarizine, 10 mg per day, underwent single photon emission computer tomography (SPECT) using [123I] labeled iodobenzamide, a ligand with high affinity and high specificity for D2 receptors. There was a reduction of the dopamine D2 receptor binding potential in all patients compared to age-matched controls. The efficacy of flunarizine in migraine prophylaxis failed to correlate with the degree of the dopamine D2 receptor blockade. The antimigraine action of flunarizine may not involve antidopaminergic mechanisms.


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