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Objective To evaluate the therapeutic effect of Xiao'er Zhixie Paste (XZP) by using the young rat model of chronic diarrhea,and to explore its mechanism.Methods Chronic diarrhea model in young rats was induced by ig senna.Rats were ig with Montmorillonite powder of 1.62 g/kg,XZP of low,medium,and high dose (2.03,4.05,and 8.10 g/kg) for treatment.Loose stools rate,loose stool grade and diarrhea index were determined 1 and 3 d after treatment respectively.The water content of small intestine was measured and blood was collected for testing serum succinate dehydrogenase (SDH),amylase,D-xylose by colorimetric determination,testing serum D-lactic acid,IL-1 β,and TNF-α by Elisa after administration.Results The rate of loose stools in XZP 4.05 and 8.10 g/kg dose group,and diarrhea index in 8.10 g/kg dose group significantly reduced after the first treatment.The loose stools rate of XZP 2.03,4.05,and 8.10 g/kg dose group,diarrhea index,serum D-lactic acid level in 4.05,8.10 g/kg group significantly reduced,and serum D-xylose level in 8.10 g/kg dose group significantly increased 3 d after treatment.However,XZP had no significant effect on SDH,amylase activity and IL-1β,TNF-α levels.Conclusion XZP has obvious therapeutic effect on chronic diarrhea in young rats,the mechanism is to increase improve the absorptive function and permeability of intestinal tract.
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Objective To study the effects of endoplasmic reticulum stress on liver damage in young rats fed with high-fat diet.Methods We divided 48 male weaned young rats randomly into high-fat diet group and control group,which were separately fed with high-fat diet and normal diet.After feeding 8,12 and 1 6 weeks,the body weight and visceral fat of the rats were measured.The serum liver function was measured.The morphology of livers was observed by HE and transmission electron microscopy. The mRNA expressions of ATF6 and GRP78 in hepatocytes were measured with RT-PCR.Results ① The body weight and visceral fat weight of rats in high-fat diet group increased compared with those in control group (P 0.05);alanine aminotransferase at week 1 6 was increased significantly compared with that in controls (P < 0.05 ).③ Liver cells in high-fat diet group had steatosis at week 8 and the steatosis became more serious between week 12 and week 1 6.④ In high-fat diet group at week 8 there were a large number of lipid droplets in the cytoplasm,and the cell structure was close to that of normal cells;rough endoplasmic reticulum was nearly normal and the ribosome was visible.At week 12 and week 1 6,besides a large number of lipid droplets,we could also see that some substances with line-like structure deposited in rough endoplasmic reticulum pool.⑤ The expressions of ATF6 and GRP78 mRNA in hepatocytes in high-fat group at weeks 8, 12 and 1 6 were significantly increased compared with those in control group (P <0.05). Conclusion High-fat diet in infants can cause visceral fat accumulation,fatty degeneration of hepatocytes and liver injury.ATF6-mediated endoplasmic reticulum may be closely related to the liver injury which results from highfat diet.
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Aim To observe the cardioprotection of chronic intermittent hypobaric hypoxia (CIHH) against ischemia/reperfusion injury in adult and young rats.Methods Adult and postnatal male Sprague-Dawley rats were divided randomly into four groups:control 28-day group (CON28),control 42-day group (CON42), CIHH 28-day treatment group (CIHH28), and CIHH 42-day treatment group (CIHH42). CIHH animals with maternal rats were put into a hypobaric chamber 2 days before birth to get 28 days and 42 days CIHH mimicking 3000 m altitude (P_B=525 mmHg,P_(O_2)=108.8 mmHg), 5 h daily, respectively.The control animals were kept in the same environment as CIHH rats with free access to water and food except hypoxic exposure. The isolated hearts were perfused in the Langendorff apparatus, undergoing 30 min global ischemia and 60 min reperfusion.Cardiac function was recorded continuously during the whole experiment. Parameters of left ventricular function included left ventricular developing pressure (LVDP), left ventricular end-diastolic pressure (LVEDP), maximal positive (+LVdp/dt) and negative (-LVdp/dt) velocity of left ventricular pressure, coronary flow (CF) and heart rate(HR).Results ① For adult rats, there was no significant difference in the parameters of left ventricular function between CIHH28 and CON28 groups. However, the recovery of cardiac function in CIHH42 rats was much better than that in CON42, including LVDP, LVEDP, ±LVdp/dt and CF (P<0.05). ② For young rats, the basic coronary flow (CF) in CIHH rats was significant higher than that in CON rats, while other parameters of cardiac function didn't change. The recovery of cardiac function in CIHH rats was much better than that in CON rats, including LVDP, LVEDP,±LVdp/dt and CF (P<0.05).Conclusion CIHH confers cardioprotection against ischemia/reperfusion injury in rat cardiomyocytes, which is predominant in CIHH42 group and significantly affected by the age of animals. Cardioprotective effects produce more easily in young rats by CIHH.
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Objective:To study the effects of marginal vitamin A deficiency (MVAD) on the hippocampal CA1 long-term potentiation (LTP) in young rats. Methods:Six female rats were divided into two groups at random, three in MVAD group, three in control group. The rats were fed VA deficient diet (400IU VA/kg) and VA sufficient diet (6 500IU VA/kg) respectively since 3 w before coitus. Serum VA was assessed by high performance liquid chromatography (HPLC). The young rats were killed at D49. The hippocampal CA1 LTP was detected by electrophysiological technique and the ultrastructure of synapses was observed by electron microscope. Results:The changes of field excitatory postsynaptic potentials (fEPSP) slope (25.4%?2.01%) in MVAD young rats aged 7 weeks were much lower than that in control group (57.5%?8.63%). The changes of slope of fEPSP induced by MVAD in young rats could be replenished after adding retinoic acid (P0.05). The curvature in synaptic interface of MVAD group was less than that of the MVAD supplemented RA group and the control. Conclusion:MVAD during embryonic and early postnatal period can directly impair the hippocampal CA1 LTP of young rats.
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Objective To explore the effect of hemeoxygenease/carbon monoxide system on hypoxic pulumonary vascular structural remodeling. Methods Twenty six Wister rats were randomly divided into four groups:control groups( n =6),hypoxia group( n =7),hypxia+ZnPP group( n =6) and hypoxia+CO group( n =7).Pulmonary artery mean pressure(mPAP) of each rat was elaluated by using right cardiac catheterization,the ultrastructaral changes in intra acinar pulmonary muscularized arteries were observed. Results mPAP was significantly increased in hypoxic rats(22?2 31?mmHg)as compared with that of normal controls(16 57?2 51mmHg)( P