Synergistic effect of dichlorvos, dimethoate and malathion mixture on reproduction toxicity in male mice / 中华预防医学杂志

<p><b>OBJECTIVE</b>To evaluate the reproduction toxicity of the mixture composed of dichlorvos, dimethoate and malathion synergistic effect on male mice, and further explore its possible mechanisms.</p><p><b>METHODS</b>The 105 male mice were divided into 7 groups, including control (0 mg/kg), mix low (10.8 mg/kg), mix medium (21.5 mg/kg), mix high dose (43.0 mg/kg), dichlorvos (5.1 mg/kg), dimethoate (12.6 mg/kg) and malathion (25.3 mg/kg) group. The oral gavage for successive 35 days, and the mice were sacrificed on the 36(th) day. The body weight, and the quantity, activity and morphology of sperms were examined. The levels of sexual hormone were measured, including testosterone (T), follicle stimulating hormone (FSH), luteinizing hormone (LH) and estradiol (E(2)). Pathological changes of testicle and epididymis were observed by morphology, pathology and electron microscope.</p><p><b>RESULTS</b>After 14 days exposure, the body weights of the mice were lower in the mix-high dose group ((22.40 ± 3.07) g) than those in control group ((26.73 ± 2.82) g) (P < 0.05). After 28 days exposure, the body weights of the mice were also lower in the mix-medium dose group ((30.00 ± 4.93) g) than those in control group ((33.13 ± 3.29) g) (P < 0.05). The sperm counts and sperm motility decreased significantly as the toxic concentration arised. Comparing to control group ((373.33 ± 14.65)×10(6)/g weight of epididymis and (75.17 ± 7.68)%), the spermatozoa count and sperm motility had decreased in mix-medium and mix-high dose groups ((321.17 ± 18.19)×10(6)/g weight of epididymis, (225.00 ± 19.67)×10(6)/g weight of epididymis, and (64.67 ± 9.91)%, (57.83 ± 9.66)%), and the sperm abnormality rates were higher in mix-medium and mix-high groups ((43.33 ± 8.66)‰ and (55.00 ± 13.80)‰) comparing to those in control group ((32.67 ± 8.17)‰). Compared to those in control group (FSH (1.41 ± 0.20), E(2)(17.32 ± 2.72), LH (8.75 ± 1.32) and T (3.45 ± 0.80) nmol/L), the serum level of FSH (3.14 ± 0.62) and (3.85 ± 0.37) nmol/L, E(2) (36.81 ± 6.68) and (43.76 ± 9.82) nmol/L in mix-medium and mix-high dose group increased (P < 0.01), while the level of LH (5.21 ± 1.23) and (4.27 ± 1.09) nmol/L and T (1.37 ± 0.38) and (0.73 ± 0.18) nmol/L decreased (P < 0.01). The morphological and ultramicrostructure results of testicle and epididymis indicated that the mature sperm numbers were decreased, and the cacoplastic sperm head and the tail of spermatozoon were observed in mix-high dose groups.</p><p><b>CONCLUSION</b>The dichlorvos, dimethoate and malathion mixture had synergistic reproductive toxicity to the testicle and epididymis structure and function, and thus leading to the process of generation cell cytopoiesis abnormalities, simultaneously the hypothalamus-pituitary-gonad axis were also affected and thus resulted in parasecretion.</p>

The study of insulin resistance and leptin resistance on the model of simplicity obesity rats by curcumin / 中华预防医学杂志

<p><b>OBJECTIVE</b>To evaluate the insulin and leptin resistance of curcumin on simplicity obesity rats.</p><p><b>METHODS</b>All 50 SPF grade healthy Sprague-Dawley male initial weaning rats were used for two groups in stratified sampling by weight: 30 in treated group and 20 in control group. They were assigned to the following treatment for 8 weeks: the treated group was fed with high-fat food and the control group was fed with normal food. Eight weeks later, adiposity model rats were prepared. Groups: adiposity model rats were divided into 3 groups: model + low curcumin (1.25 g/kg), model + high curcumin (5.00 g/kg) and a model group. In addition, there also had a normal control and a control + high curcumin (5.00 g/kg) group. Ten rats in every group and all given ground feed. After intragastric administration in different doses of curcumin 4 weeks, the effects and pathological changes were observed by the blood sugar, insulin, leptin and TNF-alpha, pathology and transmission electron microscope of pancreatic gland.</p><p><b>RESULTS</b>Given 4 weeks the different dose of curcumin on the simplicity obesity rats, the significant diminished weight (435.0 +/- 37.6) g and content of lipocyte (4.78 +/- 1.87) g as compared with the obesity model control (492.3 +/- 14.8) g and (8.94 +/- 1.88) g (t values were 4.484 and 4.961 respectively, P < 0.01), level of blood sugar (4.50 +/- 0.09) mmol/L, insulin (7.43 +/- 0.65) mmol/L, leptin (3.40 +/- 0.39) mmol/L and TNF-alpha (2.42 +/- 0.19) ng/ml were significantly decreased than those of adiposity model rats (4.94 +/- 0.12) mmol/L, (9.30 +/- 0.21) mmol/L, (4.40 +/- 0.23) mmol/L and (2.86 +/- 0.49) ng/ml (t values were 8.297, 7.743, 6.247 and 2.368 respectively, P < 0.05), and there was no significant difference with the control group (4.30 +/- 0.14) mmol/L on the level of blood sugar (t = 0.399, P > 0.05). There were a lot of secretory granules with large sphere volume in beta cells of pancreatic island found by transmission electron microscope, and these secretory granules had a higher electron density than those in non-disposed groups.</p><p><b>CONCLUSION</b>By diminishing the sediment of fat, relaxing the lymphatic return, and refraining the apoptosis of beta cells, the curcumin might significantly decrease the level of insulin resistance and leptin resistance caused by the high fat diet.</p>