Effects of embryonic lead exposure on motor function and balance ability in offspring rats and possible mechanisms / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To explore the effects of embryonic lead exposure on motor function and balance ability in offspring rats and the possible mechanisms.</p><p><b>METHODS</b>An animal model of embryonic lead exposure was prepared with the use of pregnant Sprague-Dawley rats freely drinking 0.1% (low-dose group, LG) or 0.2% (high-dose group, HG) lead acetate solution. A normal control group (NG) was also set. The male offspring rats of these pregnant rats were included in the study, consisting of 12 rats in the NG group, 10 rats in the LG group, and 9 rats in the HG group. The offspring rats' motor function and balance ability were evaluated using body turning test and coat hanger test. Eight rats were randomly selected from each group, and immunohistochemistry and Timm's staining were employed to measure the expression of c-Fos and mossy fiber sprouting (MFS) in the hippocampus.</p><p><b>RESULTS</b>The HG group had a significantly longer body turning time than the NG and LG groups (P<0.05), and the LG group had a significantly longer body turning time than the NG group (P<0.05). The HG group had a significantly lower score of balance ability than the NG and LG groups (P<0.05), and the LG group had a significantly lower score of balance ability than the NG group (P<0.05). The area percentage of c-Fos-positive neurons in the hippocampal CA1 region was significantly higher in the HG group than in the other two groups (P<0.05), and it was significantly higher in the LG group than in the NG group (P<0.05). The semi-quantitative scores of MFS in the hippocampal CA3 region and dentate gyrus were significantly higher in the HG group than in the other two groups (P<0.05), and they were significantly higher in the LG group than in the NG group (P<0.05).</p><p><b>CONCLUSIONS</b>Embryonic lead exposure could impair the offspring rats' motor function and balance ability. These changes may be related to increased c-Fos expression in the hippocampal CA3 region and abnormal MFS in the hippocampal CA3 region and dentate gyrus.</p>

Effects of embryonic lead exposure on food intake and bowel movement in offspring rats and possible mechanisms / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the effects of embryonic lead exposure on food intake and bowel movement in offspring rats and possible mechanisms.</p><p><b>METHODS</b>Sprague-Dawley rats were given 0.1% (low-dose lead exposure group) or 0.2% (high-dose lead exposure group) lead acetate freely during pregnancy to establish an animal model of embryonic lead exposure. A blank control group was also established. The male offspring rats were enrolled in the study, and 10 male offspring rats from each group were selected to observe the changes in food intake, bowel movement, gastric emptying, intestine propulsion, and pathological inflammatory response in the gastric mucosa. Eight offspring rats were selected from each group, and electron microscopy and immunohistochemistry were used to observe the changes in the ultrastructure of jejunal microvilli and cell junction and the expression of cholecystokinin-8 (CCK-8) and motilin (MTL) in the feeding center, in order to reveal the possible mechanisms for abnormal gastrointestinal motility in offspring rats induced by embryonic lead exposure.</p><p><b>RESULTS</b>Compared with the control group, the low- and high-dose lead exposure groups had a significant reduction in daily food intake, a significant increase in water content of feces, a significant reduction in fecal pellet weight, and a significant increase in small intestine propulsion (P<0.05). The high-dose lead exposure group had a significant reduction in gastric emptying ability compared with the control group (P<0.05). Compared with the control group, the lead exposure groups had significantly greater pathological inflammatory changes in the gastric mucosa (P<0.05), significant reductions in the number and length of the jejunal microvilli and the number of epithelial desmosome junctions (P<0.05), a significant increase in the macula densa gap (P<0.05), and significant increases in the expression of MTL and CCK-8 in the feeding center (P<0.05), in a dose-dependent manner.</p><p><b>CONCLUSIONS</b>The degree of gastrointestinal structural injury and expression levels of MTL and CCK-8 in the feeding center are lead dose-dependent, which may be important mechanisms for changes in food intake, bowel movement, and digestive functions in offspring rats induced by embryonic lead exposure.</p>

Screening of differentially expressed genes during adipocyte differentiation by suppression subtractive hybridization technique / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To screening differentially expressed genes related to adipocyte differentiation.</p><p><b>METHODS</b>Total RNA extracted from the preadipocyte cell line SW872 was taken as the Driver and the total RNA from the differentiated adipocytes SW872 as the Tester. Suppression subtractive hybridization (SSH) was used to isolate the cDNA fragments of differentially expressed genes. The products of SSH were inserted into pGM-T vector to establish the subtractive library. The library was amplified through E.coli transformation and positive clones of the transformants were screened. Positive clones were sequenced. Nucleic acid similarity was subsequently analyzed by comparing with the data from GenBank.</p><p><b>RESULTS</b>There were 135 white clones in the cDNA library, 64 positive clones were chosen randomly and sequenced and similarity search revealed 34 genes which expressed differentially in adipocyte differentiation.</p><p><b>CONCLUSION</b>The subtracted cDNA library for differentially expressed in adipocyte differentiation has been successfully constructed and the interesting candidate genes related to adipocyte differentiation have been identified.</p>

Effect of early high fat diet on pancreatic β cellularity and insulin sensibility in young rats / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the effects of early high fat diet on sugar metaboliam, insulin sensibility and pancreatic β cellularity in young rats.</p><p><b>METHODS</b>Sixty male weaned young rats were randomly fed with high fat diet (high fat group) and normal diet (control group). The body weight, viscus fattiness and fasting plasma glucose (FPG) were measured after 3, 6 and 9 weeks. Serum insulin level was measured with radioimmunoassay. The ultrastructure of pancreas was observed under an electricmicroscope.</p><p><b>RESULTS</b>The high fat group had significantly higher body weight and visceral fat weight than the control group after 3 weeks. There were no significant differences in the FPG level between the two groups at all time points. The levels of fasting insulin and HOMAIR in the high fat group were significantly higher than those in the control group after 3, 6 and 9 weeks (P<0.01). Dilation of rough endoplasmic reticulum and mild swelling of mitochondria of islet β-cells were observed in the high fat group after 6 weeks.</p><p><b>CONCLUSIONS</b>Early high fat diet may induce a reduction in insulin sensitivity and produce insulin resistance in young rats. Endoplasmic reticulum expansion in β-cells may be an early sign of β-cell damage due to obesity.</p>