Hc-hrg-2, a glutathione transferase gene, regulates heme homeostasis in the blood-feeding parasitic nematode Haemonchus contortus.

BACKGROUND: Haemonchus contortus, a blood-feeding parasite, is constantly surrounded by large quantities of heme released from the catabolism of host red blood cells. To cope with the toxicity of free heme, H. contortus needs to uptake and detoxify the heme, a process believed to be paramount for parasite survival. METHODS: A heme-responsive gene Hc-hrg-2 was identified which is the homologue of Ce-hrg-2. The transcriptional levels in all developmental stages and heme-responsive ability of Hc-hrg-2 were analyzed by qRT-PCR. Immunofluorescence analysis and cell transfections were performed to analyze the expression pattern of Hc-HGR-2. Statistical analyses were performed with GraghPad Prism 6.0 using Student's t-test. RESULTS: To investigate the heme homeostasis of H. contortus, we first identified a heme-responsive gene Hc-hrg-2, a homolog of Ce-hrg-2 that is involved in heme transport in the hypodermis of Caenorhabditis elegans. Using qRT-PCR, we showed that Hc-hrg-2 mRNA was expressed throughout all life-cycle stages of H. contortus with the highest level in the third-stage larvae (L3s). Notably, transcription of Hc-hrg-2 in the exsheathed L3s was significantly upregulated in the presence of high concentration of heme. We found that Hc-HRG-2 protein was mainly located in the hypodermal tissues of adult H. contortus in vivo and the endoplasmic reticulum in the transfected mammalian cells. Our in vitro assay demonstrated that Hc-HRG-2 is a heme-binding protein with glutathione S-transferase activity and heme had a significant effect on its enzymatic activity when a model substrate 1-chloro-2, 4-dinitrobenzene (CDNB) was used. CONCLUSIONS: Hc-hrg-2 is a heme-responsive gene and engaged in heme homeostasis regulation in hypodermal tissues during the free-living stages of H. contortus.

Effect of erythropoietin on the expression of dynamin-related protein-1 in rat renal interstitial fibrosis.

This study aimed to observe the expression of dynamin-related protein-1 (Drp-1) in the renal interstitium in a rat model of renal interstitial fibrosis induced by unilateral ureteral obstruction (UUO). In addition, the renoprotective effect of erythropoietin in this model was investigated. A total of 81 rats were randomly assigned to sham surgery, UUO model and treatment groups. Following surgery, the rats in the treatment group were subcutaneously administered erythropoietin at a dose of 3,000 IU/kg once a week until the time of sacrifice. Rats in the sham surgery and UUO model groups were administered an identical volume of normal saline. In each group, nine rats were chosen randomly for sacrifice on days 7, 14 and 21 after surgery for histological examination of renal tissue. Renal tissue specimens were examined by hematoxylin and eosin and Masson's trichrome staining. Immunohistochemical analysis was performed to determine the expression of Drp-1 in the renal interstitium. Renal function damage, as evaluated by the measurement of serum creatinine (Cr) and blood urea nitrogen (BUN) levels, was less severe in the treatment group compared with that in the model group at day 21 (P<0.01). Compared with the UUO model group, the renal interstitial injury score and fibrotic area of the treatment group were decreased markedly at the three time points (P<0.05). The expression level of Drp-1 in the treatment group was decreased markedly at the three time points compared with that in the model group (P<0.05). In conclusion, the expression of Drp-1 is increased in rat renal interstitial fibrosis, and erythropoietin may alleviate the degree of renal interstitial fibrosis by downregulating the expression of Drp-1.

Maternal lead exposure during lactation persistently impairs testicular development and steroidogenesis in male offspring.

Lead (Pb) is a testicular toxicant. In the present study, we investigated the effects of maternal Pb exposure during lactation on testicular development and steroidogenesis in male offspring. Maternal mice were exposed to different concentration of lead acetate (200 or 2000 ppm) through drinking water from postnatal day (PND) 0 to PND21. As expected, a high concentration of Pb was measured in the kidneys and liver of pups whose mothers were exposed to Pb during lactation. In addition, maternal Pb exposure during lactation elevated, to a less extent, Pb content in testes of weaning pups. Testis weight in weaning pups was significantly decreased when maternal mice were exposed to Pb during lactation. The level of serum and testicular T was reduced in Pb-exposed pups. The expression of P450scc, P450(17α) and 17ß-HSD, key enzymes for T synthesis, was down-regulated in testes of weaning pups whose mothers were exposed to Pb during lactation. Interestingly, the level of serum and testicular T remained decreased in adult offspring whose mothers were exposed to Pb during lactation. Importantly, the number of spermatozoa was significantly reduced in Pb-exposed male offspring. Taken together, these results suggest that Pb could be transported from dams to pups through milk. Maternal Pb exposure during lactation persistently disrupts testicular development and steroidogenesis in male offspring.

Melatonin alleviates cadmium-induced cellular stress and germ cell apoptosis in testes.

Increasing evidence demonstrates that melatonin has an anti-apoptotic effect in somatic cells. However, whether melatonin can protect against germ cell apoptosis remains obscure. Cadmium (Cd) is a testicular toxicant and induces germ cell apoptosis. In this study, we investigated the effects of melatonin on Cd-evoked germ cell apoptosis in testes. Male ICR mice were intraperitoneally (i.p.) injected with melatonin (5 mg/kg) every 8 hr, beginning at 8 hr before CdCl(2) (2.0 mg/kg, i.p.). As expected, acute Cd exposure resulted in germ cell apoptosis in testes, as determined by terminal dUTP nick-end labeling (TUNEL) staining. Melatonin significantly alleviated Cd-induced testicular germ cell apoptosis. An additional experiment showed that spliced form of XBP-1, the target of the IRE-1 pathway, was significantly increased in testes of mice injected with CdCl(2). GRP78, an endoplasmic reticulum (ER) chaperone, and CHOP, a downstream target of the PERK pathway, were upregulated in testes of Cd-treated mice. In addition, acute Cd exposure significantly increased testicular eIF2α and JNK phosphorylation, indicating that the unfolded protein response (UPR) pathway was activated by CdCl(2). Interestingly, melatonin almost completely inhibited Cd-induced ER stress and the UPR in testes. In addition, melatonin obviously attenuated Cd-induced heme oxygenase (HO)-1 expression and protein nitration in testes. Taken together, these results suggest that melatonin alleviates Cd-induced cellular stress and germ cell apoptosis in testes. Melatonin may be useful as pharmacological agents to protect against Cd-induced testicular toxicity.

Crosstalk between endoplasmic reticulum stress and mitochondrial pathway mediates cadmium-induced germ cell apoptosis in testes.

Cadmium (Cd) is associated with male infertility and poor semen quality in humans. Increasing evidence demonstrates that Cd induces testicular germ cell apoptosis in rodent animals. However, the molecular mechanisms of Cd-induced testicular germ cell apoptosis remain poorly understood. In the present study, we investigated the role of endoplasmic reticulum (ER) stress on Cd-evoked germ cell apoptosis in testes. We show that spliced form of XBP-1, the target of the IRE1 pathway, was significantly increased in testes of mice injected with CdCl(2). GRP78, an ER chaperone, and CHOP, a downstream target of the PERK pathway, were upregulated in testes of Cd-treated mice. In addition, acute Cd exposure significantly caused eIF2α and JNK phosphorylation in testes, indicating that the unfolded protein response pathway in testes was activated by Cd. Interestingly, phenylbutyric acid (PBA), an ER chemical chaperone, attenuated Cd-induced ER stress and protected against germ cell apoptosis in testes. In addition, PBA significantly attenuated Cd-evoked release of cytochrome c from mitochondria to cytoplasm in testes. Taken together, these results suggest that crosstalk between ER stress signaling and mitochondrial pathway mediates Cd-induced testicular germ cell apoptosis.

Effects of maternal cadmium exposure during late pregnant period on testicular steroidogenesis in male offspring.

Cadmium (Cd) is a testicular toxicant and endocrine disruptor. In the present study, we investigated the effects of maternal Cd exposure during the late pregnant period on testicular development and steroidogenesis in male offspring. Pregnant mice were injected intraperitoneally with CdCl(2) (0.5mg/kg) daily from gestational day (gd) 13 to gd 17. As expected, fetal weight and crown length were significantly decreased in pups whose mothers were exposed to Cd. Importantly, absolute and relative weights of testes were significantly decreased in male fetuses. In addition, maternal Cd exposure during pregnancy markedly reduced serum T level and downregulated the expression of steroidogenic acute regulatory (StAR) protein, P450scc, P45017α and 17ß-HSD in testes of male fetuses. Interestingly, the level of serum and testicular T at adulthood remained decreased in male offspring of Cd-exposed mice. Correspondingly, the expression of testicular P450scc was downregulated in male adult offspring whose mothers were exposed to Cd during pregnancy. Fertility analysis found that the number of live fetuses per litter in F2 generation was significantly decreased in Cd-treated group. Additional experiment showed that placental Cd level was increased about 750 folds in dams injected with Cd. However, only traces of blood Cd was measured in fetuses whose mothers were exposed to Cd during the late pregnant period. Taken together, these results suggest that placenta could deter most of Cd from passing from dams to fetuses. The impairments on testicular steroidogenesis in male offspring could not be attributed to a direct action of Cd on fetal testes.

Gender-specific impairments on cognitive and behavioral development in mice exposed to fenvalerate during puberty.

In human and rodent models, endocrine disrupting chemicals (EDCs) interfere with the development of cognition and behaviors. Fenvalerate is a potential EDC. The purpose of this study was to examine whether pubertal fenvalerate exposure altered behavioral development. Mice were orally administered with either vehicle or fenvalerate (7.5 or 30 mg/kg/day) from postnatal day (PND) 28 to PND56. Learning and memory were assessed by Morris Water Maze. Aggressive performance was evaluated by aggressive behavior test. Anxiety-related activities were detected by three tests: open-field, plus-maze and black-white alley. Sensorimotor function was analyzed using beam walking and tightrope. Results found that the impairment for spatial learning and memory was more severe in fenvalerate-exposed female mice than in male mice. In addition, pubertal fenvalerate exposure inhibited aggressive behavior in males. Moreover, pubertal fenvalerate exposure increased anxiety activities in females. Altogether, these results suggest that pubertal fenvalerate exposure impairs spatial cognition and behavioral development in a gender-dependent manner. These findings identify fenvalerate as candidate environmental risk factors for cognitive and behavioral development, especially in the critical period of development.

Fenvalerate induces germ cell apoptosis in mouse testes through the Fas/FasL signaling pathway.

Fenvalerate has a potentially adverse effect on male reproduction and spermatogenesis, whereas the precise mechanism remains obscure. The present study investigated the effects of fenvalerate on germ cell apoptosis in testes. Adult male mice were administered with fenvalerate (15 or 60 mg/kg) by gavage for 28 days. Germ cell apoptosis was determined by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL). The number of TUNEL+ germ cells per tubule and the percentage of tubules with TUNEL+ germ cells were significantly increased in testes of mice treated with fenvalerate in a dose-dependent manner. TUNEL+ germ cells were observed mainly in stages VII-VIII and also stages IX-XII seminiferous tubules in testes. Additional experiments showed that fenvalerate increased the level of active caspase-8 and caspase-3 in testes. In addition, fenvalerate upregulated the expression of Fas and FasL in testes. No significant difference on the expression of Bcl-2 and Bax in testes was observed between fenvalerate-treated mice and controls. Fenvalerate did not affect the leakage of cytochrome c from mitochondria into cytoplasm. In addition, fenvalerate did not cause the activation of caspase-9 in testes. Taken together, these results suggest that fenvalerate induces germ cell apoptosis in testes through the Fas/FasL signaling pathway.

Effects of pubertal fenvalerate exposure on testosterone and estradiol synthesis and the expression of androgen and estrogen receptors in the developing brain.

Fenvalerate is a potential endocrine disruptor. Several studies have demonstrated that fenvalerate disrupts testosterone (T) synthesis in testes. T and estradiol (E(2)) are de novo synthesized in the developing brain. Thus, the aim of the present study was to investigate the effects of pubertal fenvalerate exposure on the synthesis of T and E(2) and the expression of androgen receptor (AR) and estrogen receptors (ERs) in cerebral cortex. CD-1 mice were orally administered daily with either vehicle or fenvalerate (7.5 or 30 mg/kg) from postnatal day (PND) 28 to PND56. The level of T and E(2) in cerebral cortex was significantly decreased in males exposed to fenvalerate. In agreement with the decrease in T and E(2) syntheses, the expression of 17ß-HSD, a key enzyme for T synthesis, was significantly reduced in cerebral cortex of fenvalerate-exposed males. Conversely, in females, the expression of 17ß-HSD in cerebral cortex was mildly up-regulated by fenvalerate and the level of T and E(2) was mildly increased. Pubertal fenvalerate exposure had no effect on the expression of StAR, P450(17α) and P450scc, the key enzymes for T synthesis, and P450 aromatase, the key enzyme for E(2) synthesis, in cerebral cortex of males and females. Interestingly, the expression of AR in cerebral cortex was up-regulated in male and female mice exposed to fenvalerate, whereas pubertal fenvalerate exposure did not affect the level of ERα and ERß in cerebral cortex. Taken together, these results suggest that pubertal fenvalerate exposure disrupts T and E(2) synthesis and the expression of AR in cerebral cortex. These changes of steroid status in the developing brain might be deleterious for neurobehavioral development.

Maternal cypermethrin exposure during lactation impairs testicular development and spermatogenesis in male mouse offspring.

Within the last decade, numerous epidemiological studies have demonstrated that endocrine disruptors are a possible cause for a decline in semen quality. Cypermethrin is a widely used pyrethroid insecticide, but little is known about its potentially adverse effects on male reproduction. In the present study, we investigated the effects of maternal cypermethrin exposure during lactation on testicular development and spermatogenesis in male offspring. Maternal mice were administered with cypermethrin (25 mg/kg) by gavage daily from postnatal day 0 (PND0) to PND21. Results showed that the weight of testes at PND21 was significantly decreased in pups whose mothers were exposed to cypermethrin during lactation. Maternal cypermethrin exposure during lactation markedly decreased the layers of spermatogenic cells, increased the inside diameter of seminiferous tubules, and disturbed the array of spermatogenic cells in testes of pups at PND21. In addition, maternal cypermethrin exposure during lactation markedly reduced mRNA and protein levels of testicular P450scc, a testosterone (T) synthetic enzyme. Correspondingly, the level of serum and testicular T at weaning was significantly decreased in pups whose mothers were exposed to cypermethrin during lactation. Although the expression of testicular T synthetic enzymes and serum and testicular T in adulthood had restored to control level, the decreased testicular weight and histological changes were irreversible. Importantly, the number of spermatozoa was significantly decreased in adult male offspring whose mothers were exposed to cypermethrin during lactation. In conclusion, maternal cypermethrin exposure during lactation permanently impairs testicular development and spermatogenesis in male offspring, whereas cypermethrin-induced endocrine disruption is reversible.

[The nutritional status of reproductive women at one year after the disaster of Earthquake in Wenchuan].

OBJECTIVE: To evaluate the effects of Wenchuan Earthquake on the nutritional status and the prevalence of nutritional anemia, vitamin A deficiency (VAD) and vitamin D deficiency among reproductive women (15 - 44 years old) in the disaster areas one year after the Earthquake. METHODS: A nutritional survey was conducted in 3 counties in April 2009, one year after the Earthquake. Two towns from each county were selected as study sites, and this survey recruited 58 pregnant, 66 lactating and 242 non-pregnant-non-lactating women. A comparison was made to the results of 2002 Chinese Nutrition and Health Survey. RESULTS: The cereals and roots intakes of the pregnant, lactating and non-pregnant-non-lactating women living in the disaster area were (426.8 ± 271.8), (568.0 ± 306.1), and (483.0 ± 277.7) g/d respectively, which were almost the same results (486.8, 509.3 and 495.1 g/d, respectively) from 2002 National Nutrition and Health Survey. The fat and oil intakes were (41.9 ± 51.6), (55.5 ± 69.2), and (66.9 ± 125.7) g/d, respectively, which were also the same ad the results (45.2, 43.9 and 41.4 g/d, respectively) from 2002 National Nutrition and Health Survey. The intakes of meats and poultries were only (58.1 ± 67.7), (76.3 ± 218.7), and (23.9 ± 29.6) g/d respectively, which were much lower than the recommended food intakes from the Branch of Maternal and Child Nutrition of Chinese Nutrition Society. The vitamin A deficiency and marginal deficiency prevalence were 6.9% (24/347) and 18.2% (63/347), respectively. The deficiency and insufficiency of vitamin D was sum to 93.9% (323/344). The prevalence of anemia was 32.6% (112/344). 51.0% (171/335) reproductive women were iron deficient, and 61.6% (210/347) women were suffering zinc deficiency. CONCLUSION: The study findings indicated that the dietary structure was seriously effected by the Earthquake. The sources from animal and legume products were relatively low. The micronutrients nutritional status was poor. The vitamin A, vitamin D, and iron, zinc deficiencies were highly prevalent in the disaster area.

[The nutritional status among children under 60 months year-old after one year of the Earthquake in Wenchuan].

OBJECTIVE: To evaluate the effects of Wenchuan Earthquake on the nutritional status, growth, and the prevalence nutritional anemia, vitamin A deficiency (VAD) and vitamin D deficiency among children under 60 months old living in the disaster areas. METHODS: A nutritional survey was conducted in April 2009. The survey recruited 466 under 60 months old children, including 162 children aged 0 months old and 304 children aged 24 - 59 months old. The children's growth status, prevalence of anemia, and the iron deficiency prevalence, vitamin A, D, B(12), folic acid status were measured. The study findings were compared to the results from 2002 Chinese Nutritional and Health Survey. RESULTS: The exclusive breast milk feeding rate among infants under 6-months was 58.8% (30/51). Among the 0 - 23 months old children, only 10.7% (16/150) got breast feeding within one hour after delivery. Ninety-two per cent (149/162) 0 - 23 months old children never received any nutrient supplements. The average cereals and roots intakes of the 24 - 59 months old children living in the disaster area were (267.2 ± 154.3) g/d, higher than the result of rural children average (178.75 g/d) of 2002 National Nutrition and Health Survey (u = 9.995, P < 0.01). The average intakes of vegetables, aquatic products, meat and poultries were (63.6 ± 56.7), (2.6 ± 7.9), (19.4 ± 24.0) g/d, respectively, significantly lower than 2002 results 135.05, 8.82 and 32.23 g/d (u = 21.971, 13.728 and 9.321, P < 0.01). Fruits, dairy products and legumes intakes were (102.2 ± 110.8), (65.2 ± 123.8) and (20.5 ± 29.0) g/d, respectively, higher than 2002 results (32.81, 2.87 and 6.50 g/d; u = 10.919, 8.778 and 8.417, P < 0.01). The prevalence of vitamin A deficiency and marginal deficiency was 15.4% (29/188) and 30.3% (57/188), respectively. The sum of vitamin D deficiency and insufficiency was 92.0% (183/199). The prevalence of anemia of the 0-months old children and 24 - 59 months old children was 47.5% (77/162) and 21.5% (60/279), respectively. The prevalence of iron and zinc deficiencies was 45.7% (86/188) and 65.5% (127/197). The prevalence of stunt was 13.6% (38/279) among the 24 - 59 months old children. CONCLUSION: The results indicated that the dietary structure of the children living in the disaster area was not ideal. Although, the intakes of energy and protein supporting foods could meet the requirements, but the dietary lacks of meats, poultries, dairy products, legume products, aquatic products and vegetables. The vitamin A, vitamin D deficiency, iron and zinc deficiencies are of a high prevalence in the disaster area.

[The nutrition status of special population living in the areas affected by Wenchuan Earthquake after 3 months].

OBJECTIVE: To investigate and analyze the nutritional status of infants, preschool and primary school students, pregnant and lactating women in Wenchuan earthquake disaster area after 3 months. METHODS: In August 2008, the nutritional and health status information of special population were collected and evaluated using the questionnaires, anthropometric and hemoglobin concentration measurements from four settlements of villages and towns in Mao and Mianzhu Country of Sichuan and Kang Country and Wudu District in Gansu provinces. A total of 236 infants aged below 36 months, 48 preschool children, 368 primary students, 32 pregnant women and 72 lactating women were investigated. Principal investigator indexes included the low body weight, growth retardation, anemia prevalence, two-week prevalence of diarrhea and respiratory disease, food intake and nutrition-related diseases, the percentage of patients morbidity of 36 months infants, preschool and primary school students; the prevalence of anemia, the prevalence of nutrition-related diseases of pregnant and lactating women. RESULTS: The stunting prevalence was 14.6% (34/236) and the anemia prevalence was up to 40.1% (61/236) among infants younger than 36 months. Besides, the percentages of infants and young children suffered from the respiratory-infected disease and diarrhea within recent two weeks were 40.4% (95/236) and 30.2% (71/236) respectively. The percentage of low body weight of preschool children was 14.6% (7/48) and the growth retardation and anemia prevalence was 14.6% (7/48) and 39.6% (19/48), respectively. Among primary students, 6.3% (23/368) showed growth retardation and 12.2% (45/368) were anemia. The prevalence of anemia status of pregnant women and lactating mothers were 53.9% (17/32) and 24.4% (18/72) respectively. The main food composition of 45.8% (33/72) lactating women were grain and vegetables, 29 (40.3%), 32 (44.4%), 28 (38.9%) and 53 (73.6%) lactating women did not have animal originated (including meat, aquatic, livestock and poultry products) food, eggs, beans and their products, milk and dairy products, respectively. CONCLUSION: Special population lived in disaster area have suffered different degree of malnutrition. The main dietary pattern was vegetable food. The consumption of meat, eggs, milk and milk products was relatively insufficient.

Mitochondrial signaling pathway is also involved in bisphenol A induced germ cell apoptosis in testes.

Bisphenol A (BPA) is a potential endocrine disruptor and testicular toxicant. An earlier study showed that BPA-induced germ cell apoptosis through the Fas/FasL apoptotic pathway. In the present study, we aimed to investigate whether the mitochondrial pathway is also involved in the process of BPA-mediated germ cell apoptosis in testes. Male mice were administered with BPA (160 or 480 mg/kg) by gavage daily from postnatal day 35 (PND35) to PND49. Germ cell apoptosis in testes was determined by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL). As expected, the number of TUNEL+ germ cells per tubule and the percentage of tubules with TUNEL+ germ cells were significantly increased in testes of mice treated with BPA during puberty. TUNEL+ germ cells were observed mainly in stages VII-VIII seminiferous tubules in testes. An increase in the level of Fas and FasL was observed in testes of mice exposed to BPA during puberty. In addition, pubertal BPA exposure evoked the activation of caspase-8 and caspase-3 in testes. Interestingly, pubertal BPA exposure also caused the translocation of cytochrome c from mitochondria into cytosol. In addition, pubertal BPA exposure upregulated the level of Bax and active caspase-9 in testes. Taken together, these results suggest that pubertal BPA exposure induces germ cell apoptosis in testes through not only the Fas/FasL signaling pathway but also the mitochondrial apoptotic pathway.

Maternal fenvalerate exposure during pregnancy persistently impairs testicular development and spermatogenesis in male offspring.

Fenvalerate, a widely used pyrethroid insecticide, has been associated with poor semen quality. As yet, little is known about the effects of prenatal fenvalerate exposure on testicular development. The present study investigated the effects of prenatal fenvalerate exposure on testicular development and spermatogenesis. The pregnant mice were administered fenvalerate (30 mg/kg) by gavage daily from gestational day (gd) 13 to gd 18. The weights of testes and epididymides were significantly decreased in mice whose mothers were exposed to fenvalerate during pregnancy. Importantly, maternal fenvalerate exposure during pregnancy markedly decreased the number of mature seminiferous tubules (stages VII and VIII) in testes of adult male offspring. In addition, maternal fenvalerate exposure during pregnancy significantly reduced the number of epididymal spermatozoa in adult male offspring. Additional experiments showed that the level of serum testosterone (T) was significantly decreased in male fetuses whose mothers were exposed to fenvalerate during pregnancy. Correspondingly, mRNA and protein levels of P450(17alpha), a T synthetic enzyme, were significantly decreased in fetal testes. Moreover, the disruptive effect of prenatal fenvalerate exposure on testicular T synthesis was irreversible. In conclusion, prenatal fenvalerate exposure irreversibly impairs testicular development and spermatogenesis at least into early adulthood.

Pubertal and early adult exposure to fenvalerate disrupts steroidogenesis and spermatogenesis in mice at adulthood.

Fenvalerate, a pyrethroid insecticide used worldwide, has been shown to have a potentially adverse effect on male reproduction. Our earlier study showed that maternal fenvalerate exposure during lactation impaired testicular development in male offspring. In this study, we investigated the effects of pubertal and early adult exposure to fenvalerate on steroidogenesis and spermatogenesis in mice. Male mice were administered fenvalerate (60 mg/kg) by gavage daily from postnatal day 35 (PND35) to PND63. Results showed that sperm count was significantly decreased in fenvalerate-treated mice. In addition, fenvalerate markedly decreased the layers of spermatogenic cells, disturbed the array of spermatogenic cells and increased the number of apoptotic cells in testes. The adverse effects of fenvalerate on male reproduction seemed to be associated with a decrease in serum and testicular testosterone (T). Although pubertal and early adult exposure to fenvalerate had little effect on the number of Leydig cells in testes, mRNA and protein levels of testicular T biosynthetic enzymes including P450(17alpha) and P450scc were significantly downregulated in fenvalerate-treated mice. In conclusion, pubertal and early adult fenvalerate exposure induces a deleterious effect on steroidogenesis and spermatogenesis in adulthood. The decreased testicular T synthesis partially contributes to fenvalerate-induced impairment on spermatogenesis.

[The relationship of long-term school milk consumption and their attention, cognitive ability among children].

OBJECTIVE: To evaluate the status of attention and cognitive ability among children who consumed school milk for relative long-term period. METHODS: From July to August 2009, a cluster of 435 children aged 10-12 year-old (including 188 boys and 247 girls) were sampled in Changsha, Hunan Province and divided into two groups, which were long-term milk-consumption group (the children drank school milk four times per week and continued for over one year or one to three times per week and continued for over three years, 220 cases) and seldom milk-consumption group (the others, 215 cases). Children's growth and anemia status were evaluated, the mental work ability index (IMC) was evaluated by Alimov searching table and both the attention and memory function of children were evaluated by clinical memory scale. RESULT: The average height, hemoglobin (Hb) concentration and anemia rate in long term milk-consumed group were (147.6 ± 8.1) cm, (40.1 ± 9.0) g/L and 7.1% (15/212), and the indexes of the seldom milk-consumed group were (145.9 ± 8.3) cm, (38.7 ± 10.0) g/L and 13.3% (27/203). There were significant statistical differences (t = 2.124, 2.621; χ(2) = 4.418, all P values < 0.05). The scores of the third IMC in the long term milk-consumed group (233.6 ± 44.1) were higher than the seldom milk-consumed group (222.8 ± 42.3), (t = 2.505, P < 0.05). The scores of picture free recall (14.7 ± 5.0) and memory quotient (86.7 ± 17.2) were higher than that in the seldom milk-consumed group (13.4 ± 4.8 and 82.7 ± 16.1 respectively) (t = 2.539, 2.433; all P values < 0.05). CONCLUSION: Drinking milk for long-term can help increasing attention and memory of children.

Cypermethrin exposure during puberty disrupts testosterone synthesis via downregulating StAR in mouse testes.

Cypermethrin is a widely used synthetic pyrethroid insecticide. Previous studies showed that cypermethrin significantly decreased the fertility and reduced the number of implantation sites and viable fetuses in females impregnated by males exposed to cypermethrin. As yet, little is known about the mechanism of cypermethrin-induced reproductive toxicity. In the present study, we investigated the effects of cypermethrin exposure during puberty on steroidogenesis in mice. Young male mice were administered with cypermethrin (25 mg/kg) by gavage daily from postnatal day (PND) 35 to PND70. Results showed that the level of serum and testicular testosterone (T) was markedly decreased in cypermethrin-treated mice. Additional experiment showed that cypermethrin exposure during puberty markedly downregulated mRNA level of steroidogenic acute regulatory protein (StAR) in testes. Correspondingly, protein level of testicular StAR was significantly decreased in cypermethrin-treated mice. Cypermethrin exposure during puberty did not affect the number of Leydig cells in testes. Although cypermethrin exposure during puberty did not affect the weight of testes and epididymides, the number of sperm in the cauda epididymides was significantly decreased in cypermethrin-treated mice. Taken together, these results indicate that cypermethrin exposure during puberty significantly disrupts T synthesis via downregulating the expression of testicular StAR. The decreased T synthesis might be associated with cypermethrin-induced impairment in spermatogenesis in mice.

Age- and gender-dependent impairments of neurobehaviors in mice whose mothers were exposed to lipopolysaccharide during pregnancy.

Lipopolysaccharide (LPS)-induced intrauterine infection has been associated with neurodevelopmental injury in rodents. The purpose of the present study was to analyze the dynamic changes of neurobehaviors in mice whose mothers were exposed to LPS during pregnancy. The pregnant mice were intraperitoneally (i.p.) injected with LPS (8 microg/kg) daily from gestational day (gd) 8 to gd 15. A battery of neurobehavioral tasks was performed in mice at postnatal day (PND) 70, 200, 400 and 600. Results showed that the spatial learning and memory ability, determined by radial six-arm water maze (RAWM), were obviously impaired in two hundred-day-old female mice and four hundred-day-old male mice whose mothers were exposed to LPS during pregnancy. Open field test showed that the number of squares crossed and peripheral time, a marker of anxiety and exploration activity, were markedly increased in two hundred-day-old female mice following prenatal LPS exposure. In addition, prenatal LPS exposure significantly shortened the latency to the first grid crossing in six hundred-day-old female offspring. Moreover, sensorimotor impairment in the beam walking was observed in two hundred-day-old female mice whose mothers were exposed to LPS during pregnancy. Species-typical behavior examination showed that prenatal LPS exposure markedly increased weight burrowed in seventy-day-old male offspring and six hundred-day-old female offspring. Correspondingly, prenatal LPS exposure significantly reduced weight hoarded in two hundred-day-old female offspring. Taken together, these results suggest that prenatal LPS exposure induces neurobehavioral impairments at adulthood in an age- and gender-dependent manner.

Pubertal cadmium exposure impairs testicular development and spermatogenesis via disrupting testicular testosterone synthesis in adult mice.

Cadmium (Cd) is a well-known testicular toxicant. However, the effects of pubertal Cd exposure on testicular development and spermatogenesis remained to be elucidated. The present study investigated the effects of pubertal Cd exposure on testicular development and spermatogenesis. Male CD-1 mice were intraperitoneally injected with CdCl(2) (1mg/kg) daily from postnatal day 35 (PND35) to PND70. As expected, pubertal Cd exposure significantly decreased the number of spermatozoa in epididymides. In addition, pubertal Cd exposure markedly reduced the weights of testes, epididymides and prostate and seminal vesicle in adult mice. A significant decrease in serum and testicular testosterone (T) was observed in mice exposed to Cd during puberty. Moreover, pubertal Cd exposure markedly reduced mRNA and protein levels of testicular StAR, P450scc, P450(17alpha) and 17beta-HSD. Taken together, these results suggest that the decreased testicular T synthesis might partially contribute to pubertal Cd-induced impairment on testicular development and spermatogenesis in mice.