Tian Yu-ke

Effects of morphine, fentanyl and tramadol on human immune response

Morphine has been reported to suppress human immune response. We aimed to observe the effects of morphine, fentanyl and tramadol on NF-κB and IL-2 from both laboratory and clinical perspective. Jurkat cells were incubated with ten times clinically relevant concentrations of morphine, fentanyl and tramadol before being stimulated with PMA. NF-κB binding activity and IL-2 levels were measured. In the clinical study, 150 consenting patients were randomized into 3 groups according to the analgesics used in them, namely, group morphine (M), group fentanyl (F) and group tramadol (T). IL-2 was measured preoperatively and 1, 3 and 24 h after operation. Consequently, NF-κB activation was suppressed by morphine and fentanyl but not by tramadol. IL-2 was significantly decreased by morphine and fentanyl but not by tramadol in vitro. In the PCA patients, IL-2 was decreased in group M and increased in group F postoperatively. Whereas in group T, IL-2 was unchanged 1 h after operation but was significantly elevated 3 and 24 h after operation. Our results showed that the inhibition of morphine on IL-2 was most probably related to its suppression on NF-κB. Fentanyl had different effects on human immune response in vitro and in vivo. Tramadol may have immune enhancing effect.

Effect of touch-stimulus on the expression of C-fos and TrkA in spinal cord following chronic constriction injury of the sciatic nerve in rats.

SummaryTo study the mechanism of the innoxious touch-stimulus on the modulation of hyperalgesia and the expression of the C-fos and the nerve growth factor (NGF) receptor-TrkA in the spinal dorsal horn neurons following the chronic constriction injury (CCI) of the sciatic nerve in rats, 60 female Sprague-Dawley rats were randomly divided into sham-operation group and CCI group, with each group being further divided into 3 subgroups on the 7th, 14th and 28th day after operation (n=10). The mechanical and the thermal withdrawal threshold were assessed following the touch stiumulation after the CCI, immunohistochemical methods were employed to observe the expression of the C-fos and TrkA in spinal dorsal horn. Our results showed that the hyperalgesia appeared on the 4th day and reached the maximal level on the 14th day after operation. The expression of the C-fos also increased significantly and reached its maximal level on the 14th day after the touch-stimulus. Meanwhile, the TrkA expression was elevated significantly in both groups, as compared with basic data, and the difference was statistically significant (P<0.05). It is concluded that the level of the C-fos expression changed with the paw withdrawal threshold variation and increased markedly following the innoxious touch-stimulus. The expression of the TrkA receptors also increased gradually following the development of the neuropathic pain. The results suggest that C-fos may play a crucial role in the development of the hyperalgesia in the earlier-time of the neuropathic pain, but TrkA receptors may be involved in the long-lasting adaptive changes of the central pathway in neuropathic pain.

Immortalized rat astrocyte strain genetically modified by rat preprogalanin gene

SummaryTo construct an immortalized rat astrocyte strain genetically modified by rat preprogalanin gene (IAST/GAL) and detect its galanin (GAL) expression and secretion, a cDNA fragment of rat GAL in plasmid of pBS KS(+)-GAL was inserted into eukaryotic expression vector pcDNA3. 1 (+) by DNA recombinant technology, then the restriction enzyme digestion and DNA sequencing were carried out to evaluate the recombinant. The pcDNA3.1 (+)-GAL and pcDNA3.1(+) construct were transfected into immortalized rat astrocyte strain (IAST) by lipofectamine and the population of cells which stably integrated the construct was selected with 600 μg/mL G418. Individual clones were screened and expanded into clonal cell strains. Detection of Neo gene was used to validate the success of the transfection. Immunocytochemical staining, RT-PCR and radioimmunoassay were used to detect the expression and secretion level of GAL. The recombinant had been successfully constructed by restriction enzyme digestion and DNA sequencing. Detection of Neo gene showed that the pcDNA3.1 (+)-GAL and pcDNA3.1 (+) have been successfully transfected into IAST. After selection by using G418, IAST/GAL and IAST/Neo cell strains were obtained. IAST/GAL, IAST/Neo and IAST were immunostained positively for GAL, but the GAL average optical density of IAST/GAL was significantly higher than that of IAST/Neo and IAST (P<0.01). The level of GAL mRNA expression and the supernatant concentration of GAL in culture IAST/GAL were significantly higher than those of IAST and IAST/Neo (P<0.01), but no significant differences were found between the IAST and IAST/Neo (P>0.05). It was concluded that IAST/GAL strain was constructed successfully and it might provide a basis for the further study of pain therapy.

Effect of morphine and naloxone on release of the excitatory amino acids of spinal astrocytes induced by TNF-α

SummaryThe effect of morphine and naloxone on release of the excitatory amino acids (EAAs) of spinal astrocytes induced by TNF-α was studied. Astrocytes were purified from 2- to 3-day old SD rats and divided into 8 groups: group 1 (without any stimulatants); group 2 (10 ng/ml TNF-α); group3 (10 ng/ml TNF-α+0.5 μmol/L morphine); group 4 (10 ng/ml TNF-α+1.0 μmol/L morphine); group 5 (10 ng/ml TNF-α+2.0 μmol/L morphine); group 6 (10 ng/ml TNF-α+0.5 μmol/L naloxone); group 7 (10 ng/ml TNF-α+1.0 μmol/L naloxone); group 8 (10 ng/ml TNF-α +2.0 μmol/L naloxone). In group 2, 3, 4 and 5, 0, 0.5, 1.0 or 2.0 μmol/L morphine was added to the cells cultured with serum-free Neurobasal/B27 medium containing 10 ng/ml TNF-α respectively, while in group 6, 7 and 8, 0.5, 1.0 or 2.0 μmol/L naloxone was added respectively to the cells cultured with serum-free Neurobasal/B27 medium containing 10 ng/ml TNF-α. After 30 min incubation, high-pressure liquid chromatography (HPLC) was used to measure the levels of EAAs in all cultured cells. The results showed the level of EAAs in group 2 was significant higher than in group 1 (P<0.01). As compared with group 2, the levels of EAAs in group 3, 4 and 5 were decreased with the difference being significant between group 5 and group 2 (P<0.01) or between group 4 and group 2 (P<0.05). The levels of EAAs in group 6, 7 and group 8 was significantly lower than in group 2 (P<0.05 orP<0.01). It was concluded that TNF-α could promote the release of glutamate and aspartate from astrocytes, and morphine and naloxone might reduce the release of EAAs in cultured spinal astrocytes induced by TNF-α.