[Ruifuping pectin protects against intestinal mucosal injury in the rat exertional heat stroke model].

OBJECTIVE: To evaluate the intestinal function in rats with exertional heat stroke (EHS) and explore the protective role of Ruifuping pectin (RFP) against heat related intestinal mucosal injury. METHODS: One hundred and twenty healthy special pathogen free (SPF) male Sprague-Dawley (SD) rats were randomly divided into normothermic control group, EHS model group, hyperthermic plus drinking water group (H2O+EHS group) and hyperthermic plus pectin group (RFP+EHS group) with 30 rats in each group. The rats in the H2O+EHS group and RFP+EHS group were given water 20 mL/kg or RFP 20 mL/kg orally for 5 days during adaptive training period. After 1 week, the temperature control range was adjusted to (37±1) centigrade using the temperature control treadmill, and the rat model of EHS was reproduced by one-time high temperature exhaustive exercise. No rehydration intervention was given during the training adaptation period in the EHS model group. The rats in the normothermic control group were maintained to room temperature (25±2) centigrade and humidity (55±5)% without other treatment. Behavior tests including withdraw response, righting, and muscle strength were performed immediately after onset of EHS. Blood of inferior vena cava was collected, and the serum inflammatory cytokines [tumor necrosis factor-α (TNF-α) and interleukins (IL-6, IL-1ß, IL-10)] and activity of diamine oxidase (DAO) were detected by enzyme linked immunosorbent assay (ELISA). The intestinal mucosa was collected, after hematoxylin-eosin (HE) staining, and Chiu score was performed to assess EHS induced pathological changes under light microscope. RESULTS: The rats in the EHS model group had behavioral, inflammatory and pathological changes, such as delayed withdraw response and righting, decreased forelimb pulling, increased inflammatory index, and obvious intestinal mucosal injury, which indicated that the reproduction of the EHS model was successful. There was no significant difference in above parameters between the H2O+EHS group and the EHS model group except that the inflammatory index in the RFP+EHS group was improved. Compared with the EHS model group, the withdraw reflex to pain and righting after RFP pretreatment in the RFP+EHS group were significantly improved (righting score: 1.4±0.2 vs. 0.3±0.2, withdraw reflex to pain score: 1.0±0.1 vs. 0.2±0.1, both P < 0.05), the muscle strength was significantly increased (N: 13.0±0.5 vs. 8.2±0.6, P < 0.01). The levels of pro-inflammatory factors in the RFP+EHS group were significantly lower than those in the EHS model group [TNF-α (ng/L): 67.5±9.2 vs. 194.3±13.7, IL-6 (ng/L): 360.0±54.1 vs. 981.2±84.4, IL-1ß (ng/L): 33.7±9.0 vs. 88.7±6.1, all P < 0.01], while the level of anti-inflammatory factor IL-10 was higher than that in the EHS model group (ng/L: 208.7±10.5 vs. 103.7±7.0, P < 0.01). The degree of intestinal mucosal injury in the RFP+EHS group was less severe than that in the EHS model group, and the Chiu score and DAO were significantly lower than those in the EHS model group [Chiu score: 1.5±0.2 vs. 3.8±0.0, DAO (U/L): 83.7±6.7 vs. 128.7±10.5, both P < 0.05]. CONCLUSIONS: High temperature training can damage the intestinal barrier function, and induce endotoxemia and systemic inflammatory response syndrome (SIRS) in rats. Oral prophylactic RFP can protect the intestinal barrier function, alleviate SIRS, and promote the recovery of basic nerve reflex and muscle strength after the occurrence of EHS in rats.

XRCC1 and XPD genetic polymorphisms and susceptibility to age-related cataract: a meta-analysis.

OBJECTIVE: This meta-analysis aimed to determine the relationships between XRCC1 Arg399Gln (rs25487 G>A) and XPD Lys751Gln (rs1052559 A>C) polymorphisms and susceptibility to age-related cataract. METHODS: Medline (1966-2013), the Cochrane Library Database (Issue 12, 2013), EMBASE (1980-2013), CINAHL (1982-2013), Web of Science (1945-2013) and the Chinese Biomedical Database (CBM; 1982-2013) were searched without language restrictions. Various combinations of the keywords and MeSH terms were used to screen for potentially relevant studies, specifically "genetic polymorphisms" or "SNPs" or "variation" or "single nucleotide polymorphism" or "polymorphism" or "mutation" or "variant"; "X-ray repair cross complementing protein 1" or "Xeroderma Pigmentosum Group D Protein" or "X-ray repair cross complementing protein 1" or "Xeroderma Pigmentosum Group D Protein" or "XPD" or "Xeroderma Pigmentosum Complementation Group D Protein" or "ERCC2" or "XRCC1" or "XRCC1 DNA repair protein"; and "Cataract" or " Membranous Cataract" or " Pseudoaphakia." Meta-analyses were conducted using Stata 12.0 software. Crude odds ratios (ORs) and their corresponding 95% confidence intervals (95% CI) were calculated. RESULTS: Six independent case-control studies were included in the meta-analysis. Our results indicated that the association between the genetic polymorphisms of XRCC1 Arg399Gln G>A and XPD Lys751Gln A>C and increased susceptibility to age-related cataracts was statistically significant (XRCC1 Arg399Gln: OR=1.30, 95% CI=1.17-1.44, p<0.001; XPD Lys751Gln: OR=1.25, 95% CI=1.12-1.40, p<0.001, respectively). Ethnicity-stratified analysis indicated that the XRCC1 Arg399Gln G>A polymorphism was correlated with the development and progression of age-related cataract in China, India, and Turkey in the allele model and the dominant model. For the XPD Lys751Gln A>C variant, the association with the pathogenesis of age-related cataract in China and Turkey in the allele model and the dominant model was investigated. CONCLUSIONS: The association of XRCC1 Arg399Gln and XPD Lys751Gln polymorphisms with age-related cataract susceptibility observed in our meta-analyses supports the view that XRCC1 and XPD may play important roles in susceptibility to age-related cataract.