Follow up analysis of 6 patients with severe trimethyltin chloride poisoning for 4 years / 中华劳动卫生职业病杂志

Objective: Objective to investigate the health changes of patients with severe trimethyltin chloride (TMT) poisoning in four years. Methods: Six patients with severe TMT poisoning treated in the First Affiliated Hospital of Gannan Medical College in August 2016 were numbered 1, 2, 3, 4, 5 and 6 respectively. The patients were followed up 0.5, 2 and 4 years after poisoning and compared and analyzed. The follow-up contents include: symptom degree, score of simple mental intelligence examination scale (MMSE) and modified Rankin Scale (MRS) , cranial magnetic resonance imaging (MRI) , EEG, etc. Results: The symptoms of dizziness, headache, chest tightness, palpitation, nausea and vomiting decreased gradually in 6 patients. The symptoms of speech disorder and memory decline in No.1, 2 and 3 patients gradually increased, and the scores of MMSE and Mrs gradually decreased; Patients No.4, 5 and 6 had improved speech disorder, but their memory decreased, MMSE and Mrs scores were still flat, and mild cognitive impairment. The brain atrophy of No.1, 2 and 3 patients was aggravated, which showed obvious atrophy of hippocampus, temporal lobe, insular lobe and cerebellum and enlargement of ventricle; There was no significant change in brain atrophy in No.4, 5 and 6 patients. Conclusion: The neurotoxic symptoms in the later stage of severe TMT poisoning are still serious, and the neurotoxic time is long.

Rutin protects against trimethyltin-induced learning and memory impairment in BALB/c mice by antagonizing down-regulated synaptophysin expression / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the protective effects of rutin against learning and memory impairment induced by trimethyltin (TMT) and investigate the possible mechanism.</p><p><b>METHODS</b>Forty 6- to 9-week-old male BALB/c mice were randomized equally into saline group (control), TMT group, TMT+rutin group, and rutin group. Mouse models of learning and memory impairment were establish by acute TMT (2.25 mg/kg) exposure. In TMT+rutin and rutin treatment groups, the mice received intraperitioneal injection of rutin (10 mg/kg) for 1 week before TMT exposure. Twenty-four hours after TMT exposure, Morris water maze test was employed to test the escape latency of the mice, and the synaptophysin expression in the hippocampus and cortex were analyzed by Western blotting.</p><p><b>RESULTS</b>Compared that in TMT group, the escape latency of the mice in water maze test was significantly shorter in the other 3 groups (P<0.05); the escape latency in TMT +rutin group was similar with that in the control and rutin groups (P>0.05). Western blotting showed significantly decreased synaptophysin expression in the hippocampus and cortex in TMT group (P<0.05); synaptophysin expression in TMT +rutin group increased significantly compared with that in TMT group (P<0.05) but showed no statistical significance from that in rutin and control groups (P>0.05).</p><p><b>CONCLUSION</b>Rutin pretreatment offers protective effect against TMT-induced learning and memory impairment in mice possibly by antagonizing decreased synaptophysin in the hippocampus and cortex.</p>

Study on mechanism of trimethyltin chloride-induced apoptosis in PC12 cells / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the effects of trimethyltin chloride (TMT) on proliferation, apoptosis, oxidative damage, and NF-κB expression in PC12 cells in vitro.</p><p><b>METHODS</b>PC12 cells were treated with 0, 0.3125, 0.6250, 1.2500, 2.5000, 5.0000, 10.0000, and 20.0000 µmol/L TMT for 24 and 48 h, and MTT assay was used to evaluate cell viability. PC12 cells were treated with 1.25, 2.50, 5.00, and 10.00 µmol/L TMT for 12 and 24 h, and flow cytometry was used to measure the apoptotic rates of cells. PC12 cells were treated with 1.25, 2.50, 5.00, and 10.00 µmol/L TMT for 6 h, and the reactive oxygen species (ROS) and glutathione (GSH) levels were measured. PC12 cells were treated with 1.25, 2.50, 5.00, and 10.00 µmol/L TMT for 12 h, and Western blot was used to measure NF-κB levels.</p><p><b>RESULTS</b>Compared with solvent controls, the PC12 cells treated with 2.5000, 5.0000, 10.0000, and 20.0000 µmol/L TMT for 24 h showed significantly decreased cell viability (P < 0.05); the PC12 cells treated with 1.2500, 2.5000, 5.0000, 10.0000, and 20.0000 µmol/L TMT for 48 h showed significantly decreased cell viability (P < 0.05). The PC12 cells treated with 1.2500, 2.5000, 5.0000, and 10.0000 µmol/L TMT for 12 h had apoptotic rates of 15.30% ± 0.75%, 18.90% ± 0.61%, 22.00% ± 0.60%, and 36.50% ± 0.66%, respectively, and the PC12 cells treated with 1.25, 2.50, 5.00, and 10.00 µmol/L TMT for 24 h had apoptotic rates of 28.6% ± 0.40%, 43.54% ± 2.00%, 65.73% ± 0.71%, and 74.67% ± 0.40%, respectively, all significantly higher than those of the control group (12 h: 12.80% ± 1.00%, 24h: 16.83% ± 0.25%) (P < 0.05). The ROS fluorescence intensities of the PC12 cells treated with 1.25, 2.50, 5.00, and 10.00 µmol/L TMT were 1.42, 1.71, 1.78, and 1.89 times that of the control group (P < 0.05); the PC12 cells treated with 2.50, 5.00, and 10.00 µmol/L TMT had GSH levels of 0.17 ± 0.0, 0.20 ± 0.04, and 0.07 ± 0.03 µmol/µg protein, significantly lower than that of the control group (0.30 ± 0.01 µmol/L protein) (P < 0.05). The PC12 cells treated with 2.50, 5.00, and 10.00 µmol/L TMT had significantly higher expression of NF-κB p65 than the control group (P < 0.05).</p><p><b>CONCLUSION</b>Under our laboratory conditions, TMT can significantly inhibit proliferation and induce apoptosis in PC12 cells, which may be related to oxidative stress and NF-κB signaling pathway activation.</p>

Determination of trimethyltin chloride in urine by headspace-gas chromatography / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To establish a detection method for trimethyltin chloride in urine by the Head space-GC.</p><p><b>METHOD</b>After derivatizing trimethyltin chloride, the urines was separated by the head space-gc, and then the trimethyltin chloride detected qualitatively and quantificationally.</p><p><b>RESULTS</b>In the concentration range of 0.02 ∼ 0.40 mg/L urinary trimethyltin chloride, showed a quadratic, r = 0.9992, detection limit was 0.005 mg/L, the relative standard deviation was 1.9% ∼ 2.5%, recovery was 92.0% to 100%, the urine samples can be saved at least 90 days in -18°C refrigerator.</p><p><b>CONCLUSION</b>The instrument, reagents involved in the detection require low, the operations to processing samples are simple, high sensitivity, less interference, good reproducibility, and suitable for quantitative and qualitative analysis, convenient to promotion.</p>

Study on activities and protein and gene expression of renal H(+)-K(+)-ATPase in rats subchronic exposed to trimethyltin chloride / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the activity, protein and gene expression of renal HK-ATPase (HKA) in rats subchronic exposed to trimethyltin chloride (TMT).</p><p><b>METHODS</b>In subchronic toxic test (14-week), 55 female SD rats (age, 6 weeks) were divided randomly into 5 groups: control, low, medium, high and super high dosage, respectively, which drank water with TMT of 0, 8.20, 32.81, 131.25 and 262.50 microg x kg(-1) x d(-1) for 14 weeks. Then serum K+ levels were measured; the activities of HK-ATPase (HKA) in kidneys were detected by the method of determinated phosphorus content; Western Blot assay and real-time PCR were used to exam the protein and mRNA expression levels of HKA in kidneys, respectively.</p><p><b>RESULTS</b>The serum K+ level in super-high dosage group was (5.6 +/- 0.4) mmol/L, which was significantly lower than that [(6.9 +/- 0.3) mmol/L] in control group (P < 0.01). The HKA enzymatic activity of kidneys in low and super high dosage groups was 4.50 +/- 1.45 and 4.55 +/- 0.72 micromolPi x mg prot(-1)h(-1), respectively, which were significantly lower than that (6.55 +/- 0.77 micromol Pi x mg prot(-1) h(-1)) in control group (P < 0.05).</p><p><b>CONCLUSION</b>When rats were exposed subchronic to TMT, the renal HKA activity could reduce, but the expression levels of HKA protein and mRNA did not decrease.</p>

The protein expression profiles induced by trimethyltin chloride in Vero cells / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the biomarkers and mechanism of kidney toxicity induced by trimethyltin chloride (TMT-Cl) through analyzing the differences of protein expression profiles between vero cells and vero cells exposed to TMT-Cl.</p><p><b>METHODS</b>The differences of protein expression levels of three paired samples of vero cells and vero cells exposed to TMT-Cl were compared by two-dimensional gel electrophoresis (2-DE) and liquid chromatography-electrospray ionization-linear trap quadrupole (LC-ESI-LTQ). The differences of expression levels of Annexin A1 and α-Tubulin proteins were validated with western blot assay, and the differences of mRNA expression levels of Annexin A1 and α-Tubulin genes were detected with quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR).</p><p><b>RESULTS</b>Fifteen spots of differential expression in protein profiles between vero cells and vero cells exposed to TMT-Cl were found, and 9 of these spots were identified by LC-ESI-LTQ. The expression levels of 3 proteins (Annexin A1,similar to RAN protein and a hypothetical protein) increased and the expression levels of 6 proteins(growth factor receptor-bound protein 10, tubulin alpha 6, heterogeneous nuclear ribonucleoprotein, similar to elongation factor SIII p15 subunit, S-adenosylhomocysteine hydrolase and a hypothetical protein) reduced. The expression levels of α-Tubulin protein and mRNA significantly decreased in vero cells exposed to TMT-Cl, as compared with vero cells (P < 0.01). The expression of Annexin A1 protein in all exposure groups was significantly up-regulated, the expression of Annexin A1 mRNA in the groups exposed to 25 and 50 µmol/L TMT-Cl was significantly down-regulated, and The expression of Annexin A1 mRNA in the group exposed to 100 µmol/L TMT-Cl was significantly up-regulated (P < 0.01).</p><p><b>CONCLUSIONS</b>The results of present study suggest that 9 proteins with differential expression detected by LC-ESI-LTQ may be related to the kidney toxicity induced by TMT-Cl, which can serve as the biomarkers of early diagnosis and therapeutic effect for the kidney toxicity induced by TMT-Cl.</p>

Inducible nitric oxide synthase is involved in neuronal death induced by trimethyltin in the rat hippocampus / 대한수의학회지

Trimethyltin chloride (TMT) has been used as a neurotoxin for inducing brain dysfunction and neuronal death. Neuronal death in the hippocampus by TMT may generate excessive nitric oxide, but there are few studies about nitric oxide synthase enzyme involved in the synthesis of nitric oxide. The purpose of present study is to analyze the TMT toxicity in each region of rat hippocampus. To evaluate the involvement of nitric oxide, we analyzed the effects of aminoguanidine known as a selective inhibitor for inducible nitric oxide synthase on behavioral changes and the hippocampus of rat by TMT toxicity. 6-week-old male Sprague-Dawley rats were administered with a single dose of TMT (8 mg/kg b.w., i.p.) and the control group was similarly administered with distilled water. TMT + aminoguanidine-treated groups were administered with aminoguanidine (10 mg/kg or 100 mg/kg b.w., i.p.) for 3 days prior to TMT injection. The rats were sacrificed 2 days after TMT administration. In the TMT-treated group, a number of cell losses were seen in CA1, CA3 and the dentate gyrus. In the TMT + aminoguanidine-treated group, neuronal death was seen in CA1 and CA3, but reduced in the dentate gyrus compared to the TMT-treated group. Western blot analysis showed that cleaved caspase-3 expression was increased in the TMT-treated group compared to the control group. However, the expression significantly declined in the TMT + aminoguanidine-treated group. The present findings suggest that inducible nitric oxide synthase is involved in neuronal death induced by TMT.

Neuroprotective Effect of Lucium chinense Fruit on Trimethyltin-Induced Learning and Memory Deficits in the Rats

In order to the neuroprotective effect of Lycium chinense fruit (LCF), the present study examined the effects of Lycium chinense fruit on learning and memory in Morris water maze task and the choline acetyltransferase (ChAT) and cyclic adenosine monophosphate (cAMP) of rats with trimethyltin (TMT)-induced neuronal and cognitive impairments. The rats were randomly divided into the following groups: naive rat (Normal), TMT injection+saline administered rat (control) and TMT injection+LCF administered rat (LCF). Rats were administered with saline or LCF (100 mg/kg, p.o.) daily for 2 weeks, followed by their training to the tasks. In the water maze test, the animals were trained to find a platform in a fixed position during 6d and then received 60s probe trial on the 7th day following removal of platform from the pool. Rats with TMT injection showed impaired learning and memory of the tasks and treatment with LCF (p<0.01) produced a significant improvement in escape latency to find the platform in the Morris water maze at the 2nd day. Consistent with behavioral data, treatment with LCF also slightly reduced the loss of ChAT and cAMP in the hippocampus compared to the control group. These results demonstrated that LCF has a protective effect against TMT-induced neuronal and cognitive impairments. The present study suggests that LCF might be useful in the treatment of TMT-induced learning and memory deficit.

Biological monitoring of workers exposed to trimethyltin chloride / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate suitable biomarkers for workers exposure to trimethyltin chloride (TMT-cl).</p><p><b>METHODS</b>Urinary samples of 44 male workers from five TMT-cl occupational poisoning incidents were collected. Methyltin mercaptide stabilizers and waste plastics used in the incidents were also collected. The levels of TMT-cl in all the samples were determined by gas chromatography. The concentration of blood potassium for each poisonings was determined compared to control group (50 male workers of a food company), and the correlation between blood potassium and urinary TMT-cl were also determined.</p><p><b>RESULTS</b>TMT-cl was detected in urine of all the poisonings. The results were (0.869 +/- 0.392) microg/L (severe poisoning), (0.963 +/- 0.482) microg/L (moderate poisoning), (0.716 +/- 0.384) microg/L (mild poisoning) respectively and the difference was statistically significant (P < 0.01). But the severity of the clinical status did not seem to be closely correlated to the level of urinary TMT-cl (F = 1.88, P > 0.05). In the severe poisonings, there were no differences in urinary TMT-cl on day 4 after poisoning from day 1 (P > 0.05). In contrast, urinary TMT-cl was decreased significantly on day 4 than on day 1 in mild and moderate poisonings (P < 0.01). On day 21, levels of urinary TMT-cl of all the poisonings were higher than those of the workers exposed to TMT-cl who had no clinical status (P < 0.01). Blood potassium levels of exposed group was 77.3% which was significantly lower than normal value (P < 0.01). The concentration of blood potassium was lower than normal value (3.5 mmol/L) and was correlated with the severity of the clinical status (F = 4.45, P < 0.05). Level of urinary TMT-cl of exposed group was negatively correlated with blood potassium (r = -0.4456, P < 0.01).</p><p><b>CONCLUSION</b>Level of urinary TMT-cl can be used as exposure biomarker of TMT-cl poisoning. Blood potassium is an early biomarker of effect for TMT-cl poisoning so as to find poisoning population early.</p>

Studies on hypokalemia induced by trimethyltin chloride / 生物医学与环境科学（英文）

<p><b>OBJECTIVES</b>To determine the possible relationship between plasma potassium concentration and severity of acute trimethyltin chloride (TMT) poisoning and to assess the mechanism of TMT induced hypokalemia.</p><p><b>METHODS</b>SD rats were treated with various dosages of TMT (i.p.). All the indices were measured and analysed for determining their possible relations with plasma K+.</p><p><b>RESULTS</b>With increase of dosage, the plasma K+ level dropped rapidly, and deaths appeared more quickly. The LD50 of TMT (i.p.) was 14.7 mg/kgbw. In the low dosage group (10 mg/kgbw), the plasma K+ level dropped slowly with the lowest dosage on day 6 (4.85 mmol/L). It rose again on day 11 (5.06 mmol/L), and recovered on day 28. The poisoning signs corresponded with decline of the span of K+ level. The plasma Na+ level dropped half an hour after TMT treatment, but recovered 24 h later. In the high dosage group (46.4 mg/kgbw), the levels of plasma K+ and Na+ fell rapidly within half an hour (P < 0.05), the intracellular potassium concentration of RBC did not decrease obviously (P > 0.05), the activities of Na(+)-K(+)-ATPase and Mg(2+)-ATPase in RBC membrane were depressed remarkably (P < 0.01, P < 0.05, respectively), the plasma aldosterone concentrations rose as high as tenfold (P < 0.01), the arterial blood pH fell from 7.434 to 7.258 (P < 0.01), pCO2 was raised from 29.62 to 45.33 mmHg (P < 0.01). In the 24 h urine test, when rats were treated with TMT (21.5 mg/kgbw, i.p.), urine volume, urinary potassium, sodium and chloride increased significantly in comparison with those in the controls (P < 0.01).</p><p><b>CONCLUSION</b>TMT could induce hypokalemia in SD rats. The available evidence suggests that TMT can induce acute renal leakage of potassium. At the same time, a significant rise of plasma aldosterone may play an important role in promoting potassium leakage from kidney to result in severe hypokalemia with inhaling acid-base abnormalities produced, which aggravate the poisoning symptoms. In the end the rats would die of respiratory failure.</p>