Effects of deltamethrin on gene expression of some antioxidase, gamma glutamylcysteine synthetase and NFE2 related factor 2 (Nrf2) in brain tissue / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the effects of deltamethrin (DM) on the mRNA expression of copper-zinc dependent SOD (CuZn-SOD), glutathione reductase (GR) and gamma glutamylcysteine synthetase (gamma-GCS) light subunit (GCSl), as well as on expression of both mRNA and protein of gamma-GCS heavy subunit (GCSh) and NFE2 related factor 2 (Nrf2) in cerebral cortex and hippocampus of rats.</p><p><b>METHODS</b>Eighteen Wistar male rats were randomizedly divided into three groups, six for each group. The low dosage and high dosage DM treated groups were administrated intraperitoneally with DM (the daily dosage was 3.125, 12.500 mg/kg BWT respectively) for five consecutive days while the control group was administered intraperitoneally with olive oil. The relative amount of mRNA expression of these genes was measured by the method of reverse transcription polymerase chain reaction (RT-PCR) (n = 6). The protein level was detected by the method of immunohistochemistry and image analysis system (n = 4).</p><p><b>RESULTS</b>There was no change in mRNA expression level of CuZn-SOD, GR, GCSh and Nrf2 gene in both cerebral cortex and hippocampus tissue in rats administrated with DM. However, the mRNA level of GCSl gene in cerebral cortex of high dosage group as well as in both cerebral cortex and hippocampus of the low dosage group was significantly lower than that in corresponding tissue in the control group, and was decreased to 71.1%, 63.6% and 75.2% of mRNA level of corresponding tissue in the control group (P < 0.01). There was no obvious effect on protein level of both GCSh and Nrf2 in CA1, CA2, CA3 and dentate gyrus (DG) of hippocampus as well as on that in cerebral cortex in rats treated with DM.</p><p><b>CONCLUSION</b>Under the experimental conditions, there is no obvious effect in the mRNA expression level of CuZn-SOD, GR gene, as well as on expression of both mRNA and protein of Nrf2 gene in both cerebral cortex and hippocampus tissue in rats administered with DM. DM depresses the mRNA expression of GCSl gene, but does not affect the mRNA expression of GCSh gene.</p>

Oxidative stress of deltamethrin on rat nervous system / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the lipid peroxidation induced by deltamethrin (DM) in the cerebral cortex and hippocampus of rat.</p><p><b>METHODS</b>Wistar male rats were administrated with DM (daily dose was 3.125, 12.500 mg/kg respectively). The content of malondialdehyde (MDA) and the activity of total-superoxide dismutase (T-SOD, including Mn-SOD and CuZn-SOD), catalase (CAT), glutathione-S-transferase (GST), glutathione peroxidase (GSH-Px) and glutathione reductase (GR) in cerebral cortex and hippocampus tissue were determined. The reduced glutathione (GSH) content and gamma-glutamylcysteine synthetase (gamma-GCS) activity in cytosolic fraction of cerebral cortex and hippocampus tissue was determined by reversed-phase high performance liquid chromatographic assay with o-phthalaldehyde pre-column derivation.</p><p><b>RESULTS</b>(1) MDA content in cerebral cortex of the high dose group was significantly higher than those in the low dose group, and MDA content in hippocampus tissue of the high dose group was significantly higher than those in both the control and the low dose group after 5 d of DM exposure. (2) The activity of T-SOD and CuZn-SOD in cerebral cortex of both high and low dose group were significantly lower than that in the control group, and there was no effect on CAT activity in cerebral cortex (P < 0.01 or P < 0.05). (3) GSH content in cerebral cortex of the high dose group was significantly higher than that in control group (P < 0.05), and that in hippocampus tissue of high dose was significantly lower than that in both control and low dose group (P < 0.05). GR activity of low dose group in cerebral cortex was significantly lower than that in both control and high group [(11.80 +/- 5.15) vs (18.98 +/- 3.68), (17.35 +/- 2.47) U/mg pro] (P < 0.01). Gamma-GCS activity in hippocampus tissue of the high dose group was significantly lower than that in both control and low dose group [(1.75 +/- 0.60) vs (3.17 +/- 0.79), (2.72 +/- 0.75) nmol x mg pro(-1) x min(-1)] (P < 0.01). GR activity in hippocampus tissue of both high and low dose group was significantly lower than that in the control group [(21.63 +/- 4.92), (21.46 +/- 8.89) vs (31.22 +/- 6.97) U/mg pro] (P < 0.05).</p><p><b>CONCLUSION</b>The oxidative stress in nerve tissue, which could be resulted from effect of DM on the activity of SOD, gamma-GCS and GR and GSH content, is one of the mechanisms of neuro-toxicity induced by DM; The decreased activity of gamma-GCS and GR may be the primary cause of DM-induced decrease in that GSH content in hippocampus tissue.</p>

Effects of deltamethrin on the apoptosis and the expression of caspase-3 in rat neural cells / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the effect of deltamethrin on the apoptotic rate and the expression of caspase-3 in rat neural cells.</p><p><b>METHODS</b>Male Wistar rats were randomly divided into 5 groups: control, 5 h, 24 h, 48 h and 5 d exposed groups. Apoptotic rate and the expression of caspase-3 were measured by FACS420 Flow Cytometer; Ac-DEVD-pNa was used as a substrate to detect the activity of caspase-3.</p><p><b>RESULTS</b>Apoptotic rates in 24 h, 48 h and 5 d exposed groups in hippocampus and cerebral cortex [hippocampus: (8.45 +/- 1.02)%, (9.44 +/- 1.14)%, (7.58 +/- 0.75)%; cerebral cortex: (7.90 +/- 0.49)%, (8.01 +/- 0.87)%, (7.97 +/- 0.41)% respectively] were higher than those in the control [hippocampus: (2.97 +/- 0.36)%; cerebral cortex: (3.50 +/- 0.48)%] (P < 0.01); the activity of caspase-3 in 5 h, 24 h and 48 h exposed groups (A(405) nm in hippocampus: 0.389 +/- 0.038, 0.472 +/- 0.041, 0.295 +/- 0.049; A(405) nm in cerebral cortex: 0.321 +/- 0.068, 0.429 +/- 0.077, 0.344 +/- 0.047) and 5 d group of hippocampus (0.246 +/- 0.065) were all higher than those of the control (hippocampus: 0.184 +/- 0.054; cerebral cortex: 0.198 +/- 0.049) (P < 0.05, P < 0.01); the expression of caspase-3 in 5 h, 24 h and 48 h exposed groups increased apparently while 5 d group did not.</p><p><b>CONCLUSION</b>Exposure to high dose of deltamethrin would affect the apoptosis, the activity and expression of caspase-3 in rat neural cells. The increase in caspase-3 activity and expression occurred before the rising of neuronal apoptotic rate may be the upstream event of apoptosis.</p>