[Effect of Corydalis Rhizoma and L-tetrahydropalmatine on dopamine system of hippocampus and striatum in morphine-induced conditioned place preference rats].

To investigate the effects of Corydalis Rhizoma and L-tetrahydropalma-tine (L-THP) on the levels of dopamine neurotransmitter (DA), dopamine transporter (DAT) and the second dopamine receptor (D2R) in learning and memory-related brain areas, hippocampus and striatum, the DA, DAT and D2R were detected in conditioned place preference (CPP) rats suffered from morphine. And comparation the degree of similarity and consistency of the pharmacological effects was also studied. The rats were trained in black compartments and white ones (drug-paired compartment) with the increasing doses of morphine for 10 days (hypodermically injected from 10 mg•kg⁻¹ to 100 mg•kg⁻¹). Models of CPP were validated in those psychological dependence rats after 48 h training. The dopamine contents were detected as soon as the materials of hippocampus and striatum are harvested from rats of NS control group and model group. The DAT and D2R levels are measured by Western blot. The high, medium and low dose group of Corydalis Rhizoma are given Corydalis Rhizoma 2, 1, 0.5 g•kg⁻¹ water extraction liquid respectively (which contains L-THP were 0.274, 0.137 and 0.137 mg respectively), and the high, medium and low dose group of L-THP were given L-THP 3.76, 1.88, 0.94 mg•kg⁻¹ lavage treatment respectively, NS treatment group were lavaged normal saline for 6 days and they were killed after test of CPP, again tested DA levels and expression of DAT and D2R similar to the front of materials. The reduction effects of CPP were observed in the groups of both Corydalis Rhizoma (2, 1 g•kg⁻¹) and L-THP (3.76, 1.88 mg•kg⁻¹) subjected to medicine for 6 days (P<0.01). Compared with the NS treatment group and the model group, the higher values including in the contents of neurotransmitter dopamine were detected of hippocampus and striatum (P<0.01, P<0.05), the DAT and D2R protein expression of Corydalis Rhizoma (2, 1 g•kg⁻¹) and L-THP (3.76, 1.88 mg•kg⁻¹) increased in hippocampus and striatum (P<0.01). Learning and memory-related brain regions hippocampus and striatum was another neuroanatomical sites of action in the treatment of mental dependence of fumarate and L-THP, its mechanism was related to lowering its elevated DA neurotransmitter levels, and increasing the expression of DAT and D2R. Corydalis Rhizoma could be play 14-times roles in effect of L-THP. The similar effects were observed on the neurotransmitter dopamine, DAT and D2R in learning and memory-related brain areas, hippocampus and striatum of the morphine- dependent rats.

[Effect of Corydalis yanhusuo and L-THP on Gastrointestinal Dopamine System in Morphine-Dependent Rats].

OBJECTIVE: To investigate the protective mechanism of Corydalis yanhuso and L-THP in morphine-dependent gastrointestinal injury rats. METHODS: 180 male rats were randomly divided into nine groups, 20 rats for each group: saline group (N), model group (M), NS treatment group and three different dosage of Corydalis yanhusuo and L-THP groups (low dose group,middle dose group and high dose group). The rat CPP (conditioned place preference) model was established by injecting the rats with an increasing dosage of morphine, all groups received CPP training in a black compartments and white ones (drug-paired compartment) for ten days. At 48 h after the final training, the performance of CPP models were assessed to make sure all models were exported correctly. Then the treatment groups were administered with different concentration of Corydalis yanhuso (0.5, 1 and 2 g/kg) and L-THP (0.94, 1.88 and 3.76 mg/kg) for six days. All rats were immediately killed after finish the last CPP test. For each group, ten rats were killed to detect the contents of DA in the stomach and duodenum through the fluorescence spectrophotometer. The expression levels of D2 receptor( D2R) in different tissues (gastric cardia, gastric body, pylorus and duodenum) were checked by Western-blot in the other rats. RESULTS: In the NS treatment group, the time when rats stay in the white ones were significantly decreased compared with the Corydalis yanhusuo treated groups (1 and 2 g/kg) and L-THP treated groups (1.88 and 3.76 mg/kg) (P < 0.01), the high expression of DA contents in the stomach and duodenum were significantly decreased (P < 0.01). However the protein level of D2R were notably lower in gastric cardia, gastric body, pylorus and duodenum (P < 0.01). CONCLUSION: Injuries of the gastrointestinal tract followed lower DA contents and an abnormal increase of D2R in the stomach and duodenum of rats, which induced by morphine-dependent could be reversed by treatment with Corydalis yanhusuo and L-THP. This is one of mechanism underlying the protective effects of gastrointestinal tract in morphine-dependent rats.

[Study on effects of Corydalis yanhusuo and L-THP on dopamine of reward circuitry in conditioned place preference rats and comparison].

OBJECTIVE: To 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. METHOD: The 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. RESULT: Compared 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). CONCLUSION: The 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.

[Study on acting mechanism of anti-morphine conditioned place preference between aqueous extract of Corydalis yanhusuo and L-THP and comparison of their effects].

OBJECTIVE: To study the acting mechanism of anti-morphine conditioned place preference (CPP) between aqueous extract of Corydalis yanhusuo and L-THP and compare their effects. METHOD: The CPP model was established by injecting morphine in rats with a increasing dose for 10 days, with the initial dose of 10 g x kg(-1) and the final dose of 100 g x kg(-1), 10 mg x kg(-1) was increased each day, thus 100 mg x kg(-1) was injected by d 10. Having been treated with differential doses (2, 1 and 0.5 g x kg(-1)) of C. yanhusuo (containing L-THP: 0.153, 0.077 and 0.038 mg x kg(-1) respectively) and L-THP (3.76, 1.88 and 0.94 mg x kg(-1)) for six days, the CPP effect in rats was detected. Both colorimetry and immunohistochemistry methods were adopted to detect the content of glutamate neurotransmitter in each brain region and the expression of NR2B in VTA-NAc-PFC neuroanatomical circuit. RESULT: Compared with the physiological saline treatment group, C. yanhusuo (2, 1 g x kg(-1)) and L-THP (3.76 and 1.88 mg x kg(-1)) groups showed a notably shorter retention period of rats in white boxes (morphine-accompanied boxes) (P < 0.05 or P < 0.01) and remarkably lower glutamic acid content in VTA, NAc and PFC and NR2B expression. CONCLUSION: Both C. yanhusuo and L-THP can substantially inhibit the effect of morphine CPP, reduce the increasing glutamic acid content in VTA-NAc-PFC neuroanatomical circuit and down-regulated NR2B expression, which may be one of mechanisms on reducing the effect of morphine CPP. C. yanhusuo preparations containing L-THP (1 x ) showed 24-fold effect of L-THP monomer of single application in terms of the behaviouristics of inhibitory effect on CPP as well as the similarity in terms of transmitter glutamic acid of in VTA-NAc-PFC neuroanatomical circuit and pharmacological mechanism of NR2B.

[Molecular cloning and protein structure prediction of barley (Hordeum vulgare L.) Dhn6 gene and its expression pattern under dehydration conditions].

Dehydrins (DHNs), proteins with protective functions encoded by the late embryogenesis abundant (LEA), are differentially up-regulated at the transcriptional level under environmental stresses such as water deficit, salinity, and low temperature or in response to ABA. Data involving protein structure and expression of dehydrins could elucidate their functional roles under dehydration conditions in plants. Dhn6 gene of 1767 bp with an intron (92 bp) in six-rowed barley, a member of LEA D11, was cloned into pMD18-T vector in the present study. It shared 93.18% identity with Hordeum vulgare ssp. vulgare (GenBank accession: AF043091), encoding a protein composed of 523 amino acid residues with the predicted molecular weight of 49.68 kDa and the theoretical isoelectric point of 8.04. Analyses of domain and structure indicated that the protein was dominantly composed of 83% hydrophillic amino acid residues, with numerous imperative curls and three loosed helixes. Three-dimensional measurement revealed that the water-soluble lipid-associating protein was attributed to its twisted cable formed by reverse paralleled chains. Moreover, the putative amphipathic α-helices formed by K-segments might play roles in protecting membrane structure in barley. Significantly, relatively high accumulations of Dhn6 gene were detected after 8 h of water deficit by real-time quantitative RT-PCR. These results possibly suggested that the accumulation of Dhn6 gene could be critical for resistant dehydration in plants.