Effects of deltamethrin on neurobehavioral development of offspring of intoxicated rats / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the effects of deltamethrin on the filial brain nitric oxide synthase (NOS) activity and neurobehavioral development of the exposed lactational rats.</p><p><b>METHODS</b>Pregnant rats were randomizedly divided into the treated group and the control group. The treated group was administered orally with 3.35, 6.70 mg/kg deltamethrin every other day from postnatal day (PND) 1 to PND 19 while the control group was administered with the corn oil of same amount in the same period. The activity of NOS of filial brain and neurobehavioral functions of the filial rats were observed.</p><p><b>RESULTS</b>The lactational survival rate (81.80%:78.60%) in both treated groups was decreased significantly (P < 0.01) compared with that in the control group. The body weight of filial rats on PND 10, 21 in 6.70 mg/kg DM treated group [(16.62 +/- 2.2 8), (31.34 +/- 6.94) g] was less than those in the control group (P < 0.05). The delayed time in the filial rats in 6.70 mg/kg group was (3.05 +/- 1.20) s and the positive rates of passive escaping response in 3.35 and 6.70 mg/kg DM treated group were 22.5% and 21.5% respectively. There was the trend of the developmental increase of the activity of filial brain NOS between PND 5 and PND 21 and the NOS activity of rat brain on PND 5 in 6.70 mg/kg group [(0.60 +/- 0.07) U.mg pro(-1).h(-1)] was lower than that in the control group (P < 0.05).</p><p><b>CONCLUSION</b>Exposure to high dose of deltamethrin in lactational female rats will decrease the activity of NOS of brain and retard the neurobehavioral development of their filial rats.</p>

Effects of deltamethrin on cell survival rate and intracellular free Ca2+ concentration in primary cultured astrocytes of rat / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the effects of deltamethrin (DM) on cell survival rate and intracellular Ca(2+) ([Ca(2+)]i) concentration in primary cultured astrocytes of rat.</p><p><b>METHODS</b>The cell survival rate was measured by Typan Blue assay; the intracellular [Ca(2+)]i concentration was determined by the fluorescent Ca(2+) indicator Fura-2/AM.</p><p><b>RESULTS</b>The survival rate of astrocytes was decreased to 91.9% after astrocytes were incubated with 1 x 10(-5) mol/L DM for 72 h (P < 0.05). The cell survival rates were 89.0%, 84.8%, 81.2% and 79.2% respectively when astrocytes were administered with 1 x 10(-4) mol/L DM for 4, 12, 24 and 72 h, which were remarkably lower than control groups (P < 0.01). Comparing with controls and before DM treatment, sharp increases in [Ca(2+)]i concentration [(451.4 +/- 42.3), (536.9 +/- 47.5) and (870.9 +/- 100.5) nmol/L respectively] were observed when astrocytes were incubated with 1 x 10(-7), 1 x 10(-6) and 1 x 10(-5) mol/L DM for 5 minutes (P < 0.01). After astrocytes were treated with 1 x 10(-8), 1 x 10(-7), 1 x 10(-6), 1 x 10(-5) mol/L DM for 15 minutes, the [Ca(2+)]i concentrations were decreased to (124.3 +/- 6.0), (131.3 +/- 19.1), (118.9 +/- 1.4), (136.6 +/- 3.8) nmol/L respectively, which were significantly different from those of controls and before treatment. And this situation was almost keeping stable to 30 min.</p><p><b>CONCLUSION</b>The cell survival rate was decreased and the [Ca(2+)]i concentration was temporarily increased when astrocytes were treated with DM.</p>

Brain-derived neurotrophic factor mRNA expressions in rat brain induced by short-term in vivo exposure to deltamethrin / 中华预防医学杂志

<p><b>OBJECTIVE</b>To elucidate the mechanism of damage on central nervous system (CNS) caused by deltamethrin (DM).</p><p><b>METHODS</b>The mRNA and protein expressions of brain-derived neurotrophic factor (BDNF) in the cerebral cortex and hippocampus of the rats exposed to DM were measured by retro-transcription-polymerase chain reaction (RT-PCR), dot blot, flow cytometry analysis and immunohistochemistry.</p><p><b>RESULTS</b>After exposure to DM at high-dose (DM1, 25.0 mg x kg(-1) x d(-1), i.p.) once and low-dose (DM2, 12.5 mg x kg(-1) x d(-1), i.p.) for 5 days, the level of BDNF mRNA and protein expression in the cerebral cortex and hippocampus of the rats increased significantly. The levels of BDNF mRNA and protein expression in the cerebral cortex and hippocampus measured by of RT-PCR in the rats with DM1 and DM2 were higher than those in the controls by 48% and 56%, and 59% and 54%, respectively. And, those measured by dot blot in the rats with MD1 and MD2 were 186% and 161%, and 148% and 158% of those in the controls, respectively, basically similar to those measured by RT-PCR. Flow cytometric analysis showed that the levels of BDNF mRNA and protein expression in the cerebral cortex and hippocampus in the rats with DM1 and DM2 were higher than those in the controls by 53% and 89%, and 45% and 46%, respectively. Immunohistochemical analysis showed that protein expression in the cerebral cortex of the rats with DM1 and DM2 were 129% and 147% of those in the controls, same as the flow cytometric analysis, but those were significantly higher in the hippocampus mainly in the CA1 and DG areas of the rats with MD1 and the CA3 and DG areas of the rats with DM2.</p><p><b>CONCLUSIONS</b>DM could induce BDNF mRNA and protein expression in the cerebral cortex and hippocampus of the rats, which could play an important role in repairing of nerve damage.</p>