The Role of NF mRNA and Calpain in NF Reduction of Acrylamide Neuropathy / 生物医学与环境科学（英文）

The purpose of this study was to study the role of neurofilament (NF) mRNA and calpain in NF reduction of acrylamide (ACR) neuropathy. Male Wistar adult rats were injected i.p. every other day with ACR (20 mg/kg·bW or 40 mg/kg·bW) for 8 weeks. NF mRNA expression was detected using RT-PCR and the calpain concentration was determined using western blot analysis. The NF mRNA expression significantly decreased while the level of m-calpain and μ-calpain significantly increased in two ACR-treated rats groups regardless of the ACR dose. The light NF (NF-L) protein expression was significantly correlated with NF-L mRNA expression. Combined with previous data, the concentrations of three NF subunits were negatively correlated with the calpain levels. These findings suggest that NF-L mRNA and calpain mediated the reduction in NF of ACR neuropathy.

The effects of tea polyphenols on the injury of fibrinolytic functions induced by high-methionine dietary in rats / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the protective impact of tea polyphenols (TP) on the injury of fibrinolytic functions induced by high-methionine dietary in rats.</p><p><b>METHODS</b>50 male Wistar rats were divided by stratified based on body weight into 5 groups with 10 in each group: namely control group, model group, low-dose TP group, medium-dose TP group and high-dose TP group. The rats in model group and TP groups were fed with 3% methionine dietary, control group rats with routine diet. In addition, rats in low-dose, medium-dose and high-dose TP groups were treated with TP at 50, 100 and 200 mg/kg dosage respectively by gavages every day, control group and model group rats were given with same amount distilled water. The animals were sacrificed after 8 weeks. The levels of tissue-type plasminogen activator (t-PA) and type-1 plasminogen activator inhibitor (PAI-1) in plasma were determined by ELISA assays, mRNA levels of t-PA and PAI-1 in aortic arch were detected by RT-PCR, t-PA and PAI-1 expression in aortic arch were detected by immunohistochemistry strept-avidin-biotin complex (SABC).</p><p><b>RESULTS</b>After experiment, the t-PA expression of aortic arch in control group, model group, low-dose TP group, medium-dose TP group and high-dose TP group were 133.03 ± 10.14, 95.46 ± 11.08, 111.97 ± 11.91, 130.23 ± 10.80, 139.39 ± 9.41 (F = 14.15, P < 0.01), respectively, and the PAI-1 expression were 90.91 ± 8.67, 166.76 ± 12.18, 139.63 ± 12.71, 134.66 ± 13.19, 109.49 ± 10.82 (F = 31.44, P < 0.01). The t-PA concentration of plasma were (10.69 ± 1.26), (6.13 ± 0.92), (8.56 ± 1.19), (9.69 ± 0.92), (11.97 ± 1.08) ng/ml, respectively (F = 41.98, P < 0.01), and the PAI-1 concentration of plasma were (6.31 ± 0.81), (16.98 ± 1.27), (11.39 ± 0.82), (8.46 ± 0.67), (8.08 ± 0.91) ng/ml, respectively (F = 207.74, P < 0.01). The mRNA levels of t-PA in aortic arch were 1.12 ± 0.02, 0.75 ± 0.14, 1.01 ± 0.09, 0.95 ± 0.08, 1.05 ± 0.13 (F = 5.77, P < 0.05), and the mRNA levels of PAI-1 in aortic arch were 1.25 ± 0.11, 1.74 ± 0.06, 1.23 ± 0.05, 1.09 ± 0.14, 1.23 ± 0.04 (F = 23.56, P < 0.01).</p><p><b>CONCLUSION</b>The results indicate that TP seems to have regulatory function on transcription and protein levels of t-PA and PAI-1, in addition to maintaining the balance between PAI-1 and t-PA and healing the injury of fibrinolytic functions in rats induced by high-methionine dietary.</p>

Effect of phenylmethylsulfonyl fluoride pretreated on neurofilament subunits in spinal cords of hens administrated with tri-o-cresyl phosphate / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the dynamic changes of neurofilaments (NFs) proteins in spinal cords of hens with phenylmethylsulfonyl fluoride (PMSF) pretreatment for exploring the mechanism of tri-o-cresyl phosphate (TOCP)-induced delayed neuropathy (OPIDN).</p><p><b>METHOD</b>Adult Roman hens were randomly divided into three groups, control, TOCP and PMSF + TOCP. Birds in PMSF + TOCP set were pretreated with PMSF, 24 hours later, hens in both TOCP group and PMSF + TOCP group were administrated with TOCP at a single dosage of 750 mg/kg. Then all animals were sacrificed on the corresponding time-points of 1, 5, 10, and 21 days respectively after dosing of 750 mg/kg TOCP. The spinal cords were dissected, homogenized, and centrifuged at 100,000 x g. The levels of high molecular neurofilament (NF-H), medium molecular neurofilament (NF-M) and low molecular neurofilament (NF-L) in both pellet and supernatant fractions of spinal cords were determined by SDS-PAGE and Western-blotting.</p><p><b>RESULTS</b>The hens in TOCP group showed paralysis gait at the end of 21-day experimental period. The levels of NFs proteins in spinal cords changed obviously. Compared with control, the NFs in pellet showed a dramatic decrease on day 10 and then followed by a recovery. In the supernatant, the NFs proteins showed similar changes, which decreased significantly on day 10 and almost recovered control on day 21. Such as, NF-L, NF-M and NF-H decreased by 51%, 86% and 38% on day 10. The OPIDN signs were not observed in PMSF + TOCP group, and imbalances of NFs were obviously alleviated. Compared with control, only NF-M in pellet increased by 21% (P < 0.05) on day 21, others remained no changes; The levels of NF-H and NF-M in supernatant respectively increased by 19% and 35% on day 21, others were no significant statistical differences.</p><p><b>CONCLUSION</b>TOCP may induce imbalance of NFs levels in progress of OPIDN, and PMSF pretreatment may protect animals from OPIDN by reducing above changes, which may explain that TOCP-induced imbalance of NFs may be connected with the occurrence and development of OPIDN.</p>

Effects of garlic oil on n-hexane metabolized to 2, 5-hexanedione in mice serum / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the effects of garlic oil (GO) on n-hexane metabolized to 2, 5-hexanedione (2, 5-HD) in mice.</p><p><b>METHODS</b>Adult healthy Kunming-mice were treated with n-hexane and GO. The serum was obtained and extracted with ethyl acetate, and the levels of the serum 2, 5-HD were determined by gas chromatography.</p><p><b>RESULTS</b>(1) The concentration of 2, 5-HD in serum increased firstly after a single exposure to n-hexane (4 000 mg/kg). The peak value occurred at 10 hours after n-hexane treatment, but could hardly be detected at 20 h. (2) There was no 2, 5-HD in serum of control mice. The content of 2, 5-HD in serum increased along with the exposure dose of n-hexane. The serum 2, 5-HD contents of the 2000, 4000 and 6000 mg/kg groups mice were 8.04, 16.68 and 22.38 microg/ml at 8 h in pretreated mice, respectively, and showed significant dose-effect relationship. (3) When the different age mice were exposed to the same dose of n-hexane, the contents of 2, 5-HD in serum were significantly different after 8 hours (P<0.05). The serum 2, 5-HD level of the 5 weeks old mice (22.83 microg/ml) was much higher than the 4 (19.59 microg/ml) and 6 (16.42 microg/ml) weeks old mice. (4) When the different gender mice were exposed to the same dose of n-hexane, the concentration of 2, 5-HD in serum of female mice (13.22 microg/ml) was higher than that of the female mice (10.34 microg/ml, P<0.05). (5) GO significantly inhibited the increase of the serum 2, 5-HD levels of both the pretreatment and post-treatment groups treated with 80 mg/kg n-hexane respectively, but the pretreatment with GO exhibited the more suppressive effects than the post-treatment (P>0.05). Compared with the n-hexane group, the concentrations of serum 2, 5-HD in GO-pretreated groups mice decreased by 16.2%, 20.8%, 22.8% (P<0.05) and 32.1% (P<0.01), respectively, and showed significant dose-effect relationship.</p><p><b>CONCLUSION</b>The serum content of 2, 5-HD, the metabolite of n-hexane, is different in different genders and age mice after exposed to the same dose of n-hexane. GO can effectively inhibit the production of n-hexane metabolized to 2, 5-HD in mice serum.</p>

Expression changes of cyclin dependent kinase 5/p35 in nerve tissues of 2, 5-hexanedione intoxicated rats / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the role of cyclin dependent kinase 5 (CDK5) in 2, 5-hexanedione (HD)-induced neuropathy.</p><p><b>METHODS</b>Thirty male Wistar rats weighted 200 approximately 240 g were divided randomly into three groups, i.e. control group, 200 mg/kg HD group and 400 mg/kg HD group (n = 10 for each group). HD was administered to rats by intraperitoneal injection at dosage of 200 or 400 mg/kg for 8 weeks (five times per week) to establish the intoxicated rats model. The relative contents of CDK5, p35 and p25 were determined in cerebrum, spinal cord and sciatic nerve of rats by Western Blotting.</p><p><b>RESULTS</b>Compared with that of the control group rats, p35 contents were significantly decreased (P < 0.01) in the cytosolic fractions of cerebrum and spinal cord in both the 200 and 400 mg/kg HD intoxicated rats, while in the membrane fractions of spinal cord and sciatic nerve, p35 contents were increased significantly (P < 0.01). The changes of p25 showed the same pattern with p35. P25 contents were significantly reduced (P < 0.05) in the cytosolic (cerebrum and spinal cord) and membrane (cerebrum) fractions of both HD-treated rats and were elevated (P < 0.01) in the membrane fraction of spinal cord and cytosolic fraction of sciatic nerve. The relative amounts of CDK5 were significantly decreased (P < 0.01) in the cytosolic and membrane fractions of cerebrum in both the 200 and 400 mg/kg HD intoxicated rats. Except for membrane fraction of sciatic nerve, the significant increased (P < 0.01) of CDK5 were observed in the spinal cord and sciatic nerve of both the 200 and 400 mg/kg HD treated rats.</p><p><b>CONCLUSION</b>HD can induce significant changes of CDK5 and its activators p35, p25 in nerve tissues, which may be related to the neuropathy induced by HD.</p>

Effects of methamidophos on microtubule and microfilament proteins in sciatic nerve of hens / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the dynamic changes of alpha-tubulin, beta-tubulin and beta-actin in sciatic nerve of hen with organophosphorus ester-induced delayed neuropathy (OPIDN).</p><p><b>METHODS</b>OPIDN was induced in 10-month-old Roman hens by daily subcutaneous administration of 30 mg/kg methamidophos for 15 days. Hens were sacrificed 2, 10, and 23 days respectively after manifesting neuropathy. The sciatic nerves were dissected, homogenized and used for the determination of the alpha-tubulin, beta-tubulin and beta-actin levels by western blotting.</p><p><b>RESULTS</b>The levels of alpha-tubulin in supernatant of sciatic nerves were decreased by 6%, 15% and 25% respectively on day 2, 10 and 23 respectively, while those in pellet remained almost unchanged. beta-tubulin were decreased by 27%, 6%, 19% in pellet and 1%, 21%, 22% in supernatant of sciatic nerves on 2, 10 and 23 days. Beta-actin level in pellet of sciatic nerve increased by 24%, 48% and 17% on day 2, 10 and 23, and little changes were observed in supernatant.</p><p><b>CONCLUSION</b>Methamidophos may induced changes of alpha-tubulin, beta-tubulin and beta-actin levels in sciatic nerve of hen, which may be one of the mechanism of the contribution to the occurrence and development of OPIDN.</p>