Opioid use disorder (OUD) has become a considerable global public health challenge; however, potential medications for the management of OUD that are effective, safe, and nonaddictive are not available. Accumulating preclinical evidence indicates that antagonists of the dopamine D₃ receptor (D₃R) have effects on addiction in different animal models. We have previously reported that YQA14, a D₃R antagonist, exhibits very high affinity and selectivity for D₃Rs over D₂Rs, and is able to inhibit cocaine- or methamphetamine-induced reinforcement and reinstatement in self-administration tests. In the present study, our results illustrated that YQA14 dose-dependently reduced infusions under the fixed-ratio 2 procedure and lowered the breakpoint under the progressive-ratio procedure in heroin self-administered rats, also attenuated heroin-induced reinstatement of drug-seeking behavior. On the other hand, YQA14 not only reduced morphine-induced expression of conditioned place preference but also facilitated the extinguishing process in mice. Moreover, we elucidated that YQA14 attenuated opioid-induced reward or reinforcement mainly by inhibiting morphine-induced up-regulation of dopaminergic neuron activity in the ventral tegmental area and decreasing dopamine release in the nucleus accumbens with a fiber photometry recording system. These findings suggest that D₃R might play a very important role in opioid addiction, and YQA14 may have pharmacotherapeutic potential in attenuating opioid-induced addictive behaviors dependent on the dopamine system.
Rats ; Mice ; Animals ; Analgesics, Opioid ; Dopamine ; Heroin/pharmacology* ; Dopamine Antagonists/pharmacology* ; Receptors, Dopamine D3/metabolism* ; Morphine/pharmacology* ; Behavior, Addictive/drug therapy* ; Self Administration

Stress and emotion are associated with several illnesses from headaches to heart diseases and immune deficiencies to central nervous system. Terminalia arjuna has been referred as traditional Indian medicine for several ailments. The present study aimed to elucidate the effect of T. arjuna bark extract (TA) against picrotoxin-induced anxiety. Forty two male Balb/c mice were randomly divided into six experimental groups (n = 7): control, diazepam (1.5 mg·kg), picrotoxin (1 mg·kg) and three TA treatemt groups (25, 50, and 100 mg/kg). Behavioral paradigms and PCR studies were performed to determine the effect of TA against picrotoxin-induced anxiety. The results showed that TA supplementation increased locomotion towards open arm (EPM) and illuminated area (light-dark box test), and increased rearing frequency (open field test) in a dose dependent manner, compared to picrotoxin (P < 0.05). Furthermore, TA increased number of licks and shocks in Vogel's conflict. PCR studies showed an up-regulation of several genes, such as BDNF, IP, DL, CREB, GABA, SOD, GPx, and GR in TA administered groups. In conclusion, alcoholic extract of TA bark showed protective activity against picrotoxin in mice by modulation of genes related to synaptic plasticity, neurotransmitters, and antioxidant enzymes.
Animals ; Antioxidants ; metabolism ; Anxiety Disorders ; drug therapy ; genetics ; metabolism ; psychology ; Brain-Derived Neurotrophic Factor ; genetics ; metabolism ; Dopamine Agents ; administration & dosage ; GABA Agents ; administration & dosage ; Glutathione Peroxidase ; genetics ; metabolism ; Humans ; Male ; Mice ; Mice, Inbred BALB C ; Neuronal Plasticity ; drug effects ; Neurotransmitter Agents ; metabolism ; Phytotherapy ; Picrotoxin ; adverse effects ; Plant Bark ; chemistry ; Plant Extracts ; administration & dosage ; Serotonin Agents ; administration & dosage ; Superoxide Dismutase-1 ; genetics ; metabolism ; Terminalia ; chemistry

OBJECTIVETo analyze the clinical characteristics of the patient with tyrosine hydroxylase deficiency, and investigate it's molecular mechanism.

METHODThe clinical characteristics of a patient with tyrosine hydroxylase deficiency were summarized and analyzed, his and his family's peripheral blood specimens were collected after informed consent was signed. All exons and the intron-exon boundaries of guanosine triphosphate hydroxylase I gene, tyrosine hydroxylase gene and sepiapterin reductase gene were examined by DNA-PCR, bi-directional sequencing.

RESULTThe patient was a 3-year-old boy, presented with unexplained dystonia for 3 years, without significant impairment of intelligence. Physical examination showed limb muscle strength grade V, rigidity of extremities, hypertonicity, brisk deep tendon reflexes in limbs, without obvious abnormalities in auxiliary examination, such as brain MRI, hepatic biochemical panel, creatine kinase, and ceruloplasmin. He dramatically responded to small doses of levodopa in the follow-up for half a year. A homozygous missense change in exon 5 of TH gene, c.605G > A (p.R202H), which was a known pathogenic mutation, was found in the patient. His parents were heterozygous for the R202H mutation.

CONCLUSIONThe age of onset in tyrosine hydroxylase deficiency patients is usually within the first year of life. Unexplained dystonia and hypokinesia were the main clinical features of tyrosine hydroxylase deficiency. The dopa-responsive effects for some patients are so obvious that we should strengthen awareness of the disease. TH gene c.605G > A (p.R202H) may be a common type of causative mutations for the mild form at home and abroad.

Brain ; metabolism ; pathology ; Catecholamines ; biosynthesis ; Child, Preschool ; DNA ; genetics ; DNA Mutational Analysis ; Dopamine Agents ; administration & dosage ; therapeutic use ; Dystonic Disorders ; drug therapy ; genetics ; metabolism ; Homozygote ; Humans ; Hypokinesia ; drug therapy ; genetics ; metabolism ; Levodopa ; administration & dosage ; therapeutic use ; Male ; Muscle Rigidity ; drug therapy ; genetics ; metabolism ; Mutation, Missense ; Polymerase Chain Reaction ; Tyrosine 3-Monooxygenase ; deficiency ; genetics ; metabolism

OBJECTIVETo study the effects of dopamine and phenylephrine for treatment of hypotension during cesarean section under combined spinal epidural anesthesia (CSEA) on the stereology of the placenta.

METHODSForty puerperants undergoing cesarean section under CSEA were randomly divided into dopamine group and phenylephrine group. Ropivacaine (16 mg) was administered immediately after spinal anethesia. Blood pressure was maintained near the baseline by adjusting the drug infusion rate. Fetal blood gas, Apgar score, and placental villus microvascular stereological changes were observed during the operation.

RESULTSThe microvascular density was significantly lower in dopamine group than in phenylephrine group (P<0.05). Phenylephrine group showed significantly lower umbilical artery blood pH than dopamine group (P<0.05). The Apgar score and blood pressure were comparable between the two groups (P>0.05). Compared to the baseline, both of the two groups showed significantly lowered heart rate during the operation (P<0.01).

CONCLUSIONDopamine is associated with the risk of fetal acidosis. Phenylephrine is helpful for preventing hypotension by increasing placental blood flow and improving oxygen supply to ensure maternal and fetal safety during cesarean section.

Amides ; administration & dosage ; Anesthesia, Spinal ; Apgar Score ; Blood Gas Analysis ; Blood Pressure ; Cesarean Section ; Dopamine ; administration & dosage ; Female ; Fetal Blood ; Fetus ; Heart Rate ; Humans ; Hypotension ; drug therapy ; Infant, Newborn ; Oxygen ; Phenylephrine ; administration & dosage ; Placenta ; drug effects ; physiology ; Pregnancy ; Vasoconstrictor Agents ; administration & dosage

OBJECTIVETo discuss the protective effect of alkaloids from Piper longum (PLA) in rat dopaminergic neuron injury of 6-OHDA-induced Parkinson's disease and its possible mechanism.

METHODThe rat PD model was established by injecting 6-OHDA into the unilateral striatum with a brain solid positioner. The PD rats were divided into the PLA group (50 mg x kg(-1) x d(-1)), the madorpa group (50 mg x kg(-1) x d(-1)) and the model group, with 15 rats in each group. All of the rats were orally given drugs once a day for 6 weeks. Meanwhile, other 15 rats were randomly selected as the sham operation group, and only injected with normal saline in the unilateral striatum. The behavioral changes were observed with the apomorphine (APO)-induced rotation and rotary rod tests. The number of tyrosine hydroxylase (TH)-positive cells in rat substantia nigra and the density of TH-positive fibers in striatum were detected by tyrosine hydroxylase immunohistochemistry. The content of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione (GSH), catalase (CAT), malondialdehyde (MDA), nitric oxide (NO) and nitric oxide synthase (NOS) in rat substantia nigra and striatum were measured by the spectrophotometric method.

RESULTAfter being induced by APO, PD rats showed obvious rotation behaviors, with decreased time stay on rotary rod and significant reduction in the number of TH-positive cells in sustantia nigra and the density of TH-positive fibers in striatum. The activities of SOD, GSH-Px, CAT, the content of GSH and the total antioxidant capacity significantly decreased, whereas the activities of NOS and the content of MDA, NO significantly increased. PLA could significantly improve the behavioral abnormality of PD rats and increase the number of TH-positive cells in sustantia nigra and the density of TH-positive fibers in striatum. It could up-regulate the activities of SOD, GSH-Px, CAT, the content of GSH and the total antioxidant capacity, and decrease the content of NOS and the content of MDA, NO.

CONCLUSIONAlkaloids from P. longum shows the protective effect in substantia nigra cells of 6-OHDA-induced PD model rats. Its mechanism may be related with their antioxidant activity.

Administration, Oral ; Alkaloids ; administration & dosage ; pharmacology ; Animals ; Apomorphine ; pharmacology ; Catalase ; metabolism ; Dopamine Agonists ; pharmacology ; Dopaminergic Neurons ; drug effects ; metabolism ; pathology ; Glutathione ; metabolism ; Glutathione Peroxidase ; metabolism ; Male ; Malondialdehyde ; metabolism ; Motor Activity ; drug effects ; Neostriatum ; drug effects ; metabolism ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase ; metabolism ; Oxidopamine ; Parkinson Disease, Secondary ; chemically induced ; physiopathology ; prevention & control ; Piper ; chemistry ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Substantia Nigra ; drug effects ; metabolism ; Superoxide Dismutase ; metabolism ; Tyrosine 3-Monooxygenase ; metabolism

The aim of this study was to investigate the outcome, and optimal duration of medical treatment in children with superior mesenteric artery syndrome (SMAS). Eighteen children with SMAS were retrospectively studied. The data reviewed included demographics, presenting symptoms, co-morbid conditions, clinical courses, nutritional status, treatments, and outcomes. The three most common symptoms were postprandial discomfort (67.7%), abdominal pain (61.1%), and early satiety (50%). The median duration of symptoms before diagnosis was 68 days. The most common co-morbid condition was weight loss (50%), followed by growth spurt (22.2%) and bile reflux gastropathy (16.7%). Body mass index (BMI) was normal in 72.2% of the patients. Medical management was successful in 13 patients (72.2%). The median duration of treatment was 45 days. Nine patients (50%) had good outcomes without recurrence, 5 patients (27.8%) had moderate outcomes, and 4 patients (22.2%) had poor outcomes. A time limit of >6 weeks for the duration of medical management tended to be associated with worse outcomes (P=0.018). SMAS often developed in patients with normal BMI or no weight loss. Medical treatment has a high success rate, and children with SMAS should be treated medically for at least 6 weeks before surgical treatment is considered.
Adolescent ; Bile Reflux/diagnosis ; Child ; Child, Preschool ; Demography ; Domperidone/therapeutic use ; Dopamine Antagonists/therapeutic use ; Drug Administration Schedule ; Female ; Histamine H2 Antagonists/therapeutic use ; Humans ; Infant ; Male ; Parenteral Nutrition ; Retrospective Studies ; Superior Mesenteric Artery Syndrome/*diagnosis/drug therapy ; Time Factors ; Tomography, X-Ray Computed ; Treatment Outcome ; Weight Loss

OBJECTIVETo study and compare the effect of Corydalis yanhusuo and L-THP on dopamine neurotransmitter and D2 receptor of reward circuitry in various cerebral areas of conditioned place preference model rats and the comparison of their effects.

METHODThe CPP model was established by injecting morphine in rats with increasing doses for 10 days. The initial dose of 10 mg x kg(-1), and the final dose of 100 mg x kg(-1), with 10 mg x kg(-1) increased each day. At 48 h after the final training, CPP was adopted to detect the successful establishment of the model. On the same day (12 d), they were orally administered with 2, 1, 0.5 g x kg(-1) C. yanhusuo (containing 0.153, 0.077 and 0.038 mg L-THP) and L-THP (3.76, 1.88, 0.94 mg x kg(-1)) for six days. On 18 d, CPP test was performed again. Next day, HPLC was adopted to determine the content of dopamine neurotransmitters of reward circuitry in VTA-NAc-PFC; Immunohistochemistry and Western blotting were adopted to detect the expression of D2 receptors.

RESULTCompared with the physiological saline treatment group, C. yanhusuo (2, 1 g x kg(-1)) and L-THP (3.76, 1.88 mg x kg(-1)) groups showed that rats stayed in a notably shorter period in white boxes (morphine-accompanied boxes) (P < 0.01 or P < 0.05), and revealed a remarkably lower dopamine content in VTA, NAc and PFC and the significant increase in the expression of D2 receptor (P < 0.01 or P < 0.05).

CONCLUSIONThe down-regulation of the increased dopamine content in reward nervous circuitry and the up-regulation of the expression of D2 receptor may be one of mechanisms of C. yanhusuo and L-THP in accelerating the recession of morphine's CPP effect Regarding the inhibition of morphine's CPP effect and the effect on dopamine system, the effect of C. yanhusuo traditional Chinese medicine containing one-fold L-THP monomer is equal to that of the independent application of around 24-fold L-THP monomer.

Animals ; Berberine Alkaloids ; administration & dosage ; Brain ; drug effects ; metabolism ; physiopathology ; Conditioning, Operant ; drug effects ; Corydalis ; chemistry ; Dopamine ; metabolism ; Humans ; Male ; Morphine ; adverse effects ; Plant Extracts ; administration & dosage ; Rats ; Rats, Sprague-Dawley ; Receptors, Dopamine D2 ; genetics ; metabolism ; Substance-Related Disorders ; drug therapy ; genetics ; metabolism ; psychology

Using brain microdialysis and LC-ECD, the content of dopamine in rat brain was detected to investigate the effects of ligustrazine. A liquid chromatography-electrochemical detector method has been established and validated for the determination of dopamine in rat brain dialysate. The results indicate that ligustrazine administration by subcutaneous injection significantly increased dopamine release in rat medial prefrontal cortex, nucleus accumbens and hippocampus in a dose-related manner. The drug's effects on dopa release in rat brain could be directly detected by microdialysis combined with HPLC-ECD and this method has the preponderance over traditional neurology methods.
Animals ; Brain ; metabolism ; Chromatography, High Pressure Liquid ; Dopamine ; metabolism ; Dose-Response Relationship, Drug ; Electrochemical Techniques ; Hippocampus ; metabolism ; Injections, Subcutaneous ; Ligusticum ; chemistry ; Male ; Microdialysis ; methods ; Nucleus Accumbens ; metabolism ; Plant Roots ; chemistry ; Plants, Medicinal ; chemistry ; Prefrontal Cortex ; metabolism ; Pyrazines ; administration & dosage ; isolation & purification ; pharmacology ; Rats ; Rats, Sprague-Dawley

This study is to offer a clinical pain-depression dyad therapy of ferulic acid, the pain-depression dyad induced by reserpine was established and the dose-effect relationship of ferulic acid on ameliorating pain-depression dyad was explored. Mice were randomly divided into control group, reserpine + vechile and reserpine + ferulic acid (5, 10, 20, 40 and 80 mg x kg(-1)) groups. The reserpine treated mice were tested with thermal hyperalgesia, mechanicial allodynia and forced swimming tests, and the SOD and NO levels of hippocampus and frontal cortex were measured. Moreover, the HPLC-ECD was used to detect the changes of central monoamines concentrations. Compared with control group, reserpine can induce a significant decrease in the nociceptive threshold and increase in the immobility time of the forced swimming test. The results suggested that reserpine significantly increased the level of nitrite in hippocampus and frontal cortex and reduced the levels of SOD, 5-HT and NE in these two brain regions. However, these indexes can be a dose-dependently reversed by ferulic acid (5, 10, 20, 40 and 80 mg x kg(-1)). Ferulic acid can reverse pain-depression dyad, especially at the dose of 80 mg x kg(-1). In addition, it can influence oxidative stress and monoamine level.
Animals ; Antidepressive Agents ; administration & dosage ; pharmacology ; Coumaric Acids ; administration & dosage ; pharmacology ; Depression ; chemically induced ; complications ; metabolism ; physiopathology ; Dopamine ; metabolism ; Dose-Response Relationship, Drug ; Frontal Lobe ; metabolism ; Hippocampus ; metabolism ; Hyperalgesia ; physiopathology ; Male ; Mice ; Mice, Inbred ICR ; Nitric Oxide ; metabolism ; Norepinephrine ; metabolism ; Pain ; chemically induced ; complications ; metabolism ; physiopathology ; Pain Measurement ; Random Allocation ; Reserpine ; adverse effects ; Serotonin ; metabolism ; Superoxide Dismutase ; metabolism ; Swimming ; physiology

PURPOSE: Levodopa is the most effective anti-Parkinsonian agent. It has also been known to exhibit analgesic properties in laboratory and clinical settings. However, studies evaluating its effects on neuropathic pain are limited. The aim of the present study was to examine the anti-allodynic effects of levodopa in neuropathic rats. MATERIALS AND METHODS: Sprague-Dawley male rats underwent the surgical procedure for L5 and L6 spinal nerves ligation. Sixty neuropathic rats were randomly divided into 6 groups for the oral administration of distilled water and levodopa at 10, 30, 50, 70, and 100 mg/kg, respectively. We co-administered carbidopa with levodopa to prevent peripheral synthesis of dopamine from levodopa, and observed tactile, cold, and heat allodynia pre-administration, and at 15, 30, 60, 90, 120, 150, 180, and 240 min after drug administration. We also measured locomotor function of neuropathic rats using rotarod test to examine whether levodopa caused side effects or not. RESULTS: Distilled water group didn't show any difference in all allodynia. For the levodopa groups (10-100 mg/kg), tactile and heat withdrawal thresholds were increased, and cold withdrawal frequency was decreased dose-dependently (p<0.01). In addition, levodopa induced biphasic analgesia. Different dosage of levodopa did not impact on the rotarod time (p>0.05). CONCLUSION: Levodopa reversed tactile, cold and heat allodynia in neuropathic rat without any side effects.
Animals ; Carbidopa/administration & dosage/adverse effects/therapeutic use ; Dopamine Agents/administration & dosage/adverse effects/*therapeutic use ; Hyperalgesia/*drug therapy ; Levodopa/administration & dosage/adverse effects/*therapeutic use ; Male ; Neuralgia/*drug therapy ; Rats ; Rats, Sprague-Dawley ; Rotarod Performance Test