Objective: To investigate the possible mechanisms in acupuncture analgesia by interaction of &opioid receptor with neurotransmitter transport proteins or the Na+-K+pump. Methods: Microinjection of respective heterologous cRNA into the Xenopus oocytes as a model system, and measurement of steady-state currents under two-electrode voltage clamp. Results: The co-expression of the δ-opioid receptor with GAT1, EAAC1 or the sodium pump resulted in reducing activity of the respective transporter. Opioid receptor activation affected transporter activity in different ways: 1) GAT1 was further inhibited; 2) EAAC1 was stimulated; 3) Na+-K+ pump activity interfered with agonist sensitivity of DOR. Pump inhibition led to higher sensitivity for DPDPE. Conclusion: GABA transporter inhibition and glutamate transporter stimulation may counteract pain sensation by affecting the neurotransmitter concentration in the synaptic cleft and, therefore, may contribute synergistically to pain suppression by acupuncture. Sodium pump inhibition by endogenous ouabain may amplify these effects. These synergistic effects may be the molecular mechanism of inhibiting pain sense and/or acupuncture analgesia.

Objective K93T point mutation exists in the quinoid dihydropteridine reductase ( QDPR) of OLEFT rats which catalyzes QDPR into tetrahydrobinopterin(BH4), while dihydrofolate reductase(DHFR) can reduce QDPR to BH4, which implies crosstalk between hydrobiopterin and folate metabolism.By investigating the influence of QDPR expression on DHFR expression of NRK-52E cells, the article aimed to find out the possible underlying mechanism of QDPR gene in diabetic nephropathy ( DN). Methods Western blot was performed to identify the expression level in NRK-52E cell under high glucose ambience and DHFR pro-tein expression of OLETF rats.NRK-52E cells were transfected by the lentivirus to establish no-load overexpression, overexpressed QDPR and knockdown QDPR models.Each group was given 5.4 mmol/L normal sugar medium and 30mmol/L in high glucose ambi-ence for 72 hours'cell cultivation to simulate DN model.Observation was made on the influence of QDPR gene expression levels on DHFR in high glucose ambience. Results The western blot analysis revealed that DHFR protein decreased in NHG group( [0.33 ± 0.16] vs [0.64 ±0.5], P<0.05) and OLETF rats cortex ([0.56 ±0.16] vs [1.03 ±0.12], P<0.01).In high glucose ambi-ence, compared with LV-OCON-HG group, the protein expression of DHFR was significantly decreased in LV-QDPR-HG group ([0.12 ±0.09] vs [0.63 ±0.08], P<0.01).No difference was found in the comparison of DHFR expression levels between LV-SHQDPR-HG and LV-SHCON-HG group. Conclusion DHFR protein expression decreases in NRK-52E cells of high glucose and LOLETF rat model, which suggests that DHFR protein plays an important role in the development of DN.QDPR overexpression leads to the decreased expression of DHFR, which implies that overexpressed QDPR influences the occurrence and process of DN by down-regulating DHFR expression level.

_ Objective_ To study whether quinoid dihydropteridine reductase ( QDPR ) expression level change can affect oxidative stress of NRK-52E renal tubular cells in a high glucose environment. Methods The NRK-52E model of overexpression, knockdown QDPR gene and respective control were constructed by lentivirus. All groups were given 5. 4 mmol/L and 30 mmol/L glucose culture medium respectively to imitate normal and high glucose condition. The level of superoxide anion ( O-2 ) was detected by flow cytometer dihydroethidium method. The protein expression level of superoxide dismutase 1 (SOD1)was tested by Western blot. Results QDPR over-expression can decrease O-2(P<0. 01)and SOD1(P<0. 05)levels in high glucose condition;QDPR knockdown increases O-2(P<0. 01) and does not change SOD1. Conclusion Under high glucose condition, overexpression of QDPR gene decreases NRK-52E cell oxidative stress. Knockdown QDPR gene increases NRK-52E cell oxidative stress. QDPR gene may influence the development of diabetic nephropathy by oxidative stress.

Algorithms ; Crystallography, X-Ray ; Disulfides ; chemistry ; Models, Molecular ; Protein Conformation ; Proteins ; chemistry