Effects of heat exposure and vitamin C intervention on oxidative stress and blood pressure changes in treadmill rats / 中华劳动卫生职业病杂志

Objective: To investigate the effect of oxidative stress caused by heat exposure on the blood pressure increase of treadmill rats and the intervention of antioxidants. Methods: In June 2021, Twenty-four healthy SD male rats were randomly divided into four groups: normal temperature feeding, normal temperature treadmill, high temperature treadmill and high temperature treadmill supplementation with vitamin C groups, 6 rats in each group. The rats run on the platform in normal temperature or heat exposure environment for 30 min in the morning and in the afternoon daily, 6 days per week. The daily vitamin C supplement dose of high temperature treadmill supplementation with vitamin C group was 10 mg/kg. BP recordings were done at the end of the week. The rat vascular lipofuscin (LF) was detected by ELISA, the rat serum nitric oxide (NO) was detected by nitrate reductase method, the serum malondialdehyde (MDA) was detected by thibabituric acid method, the serum glutathione peroxidase (GPx) and superoxide dismutase (SOD) were detected by chemiluminescence method, and the serum catalase (CAT) was detected by ammonium molybdate method. The total antioxidant capacity (T-AOC) of serum was measured by iron reduction/antioxidant capacity method, and the content of nuclear erythroid 2-related factor 2 (Nrf2) in vascular tissue was measured by Western blot. The intra-group mean was compared by repeated measurement analysis of variance, and the inter-group mean was compared by single-factor analysis of variance and post-event LSD-t test. Results: Compared with the previous time point, the systolic BP and diastolic BP of the high temperature treadmill group were significantly increased at 7, 14 and 21 d, and decreased at 28 d which were higher than the initial level (P<0.05), and the systolic BP and diastolic BP values at each experimental time point were significantly higher than those of normal temperature treadmill group (P<0.001). The changes of thickening of the artery wall, no smoothing of the endodermis and irregular arrangement of muscle cells in high temperature treadmill group were observed. Compared with the normal temperature treadmill group, the content of MDA in serum, and LF in vascular tissue were significantly increased, the activities of SOD, CAT, T-AOC, the content of NO in serum, and the expression of Nrf2 in vascular tissue were significantly decreased in high temperature treadmill group (P<0.05). Compared with the high temperature treadmill group, the systolic BP and diastolic BP values at 7, 14, 21 and 28 d, the content of serum MDA and LF in vascular tissue were significantly decreased, the activities of CAT and T-AOC, and the expression of Nrf2 in vascular tissue significantly increased (P<0.05), the histopathological changes of the artery wall improved in high temperature treadmill supplementation with vitamin C group. Conclusion: Heat exposure has effect on oxidative stress, which may be related to the increase of BP. Vitamin C as an anti-oxidative enhancer can prevent those negative effects, which could alleviate the pathological changes of vessel intima in heat-exposed rats. And the Nrf2 may be a regulated factor to vascular protection.

Effect of enteral supplement of arginine on intestinal adaptation and its mechanism in experimental rats with short bowel syndrome / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To evaluate the effect of enteral supplement of arginine on intestinal adaptation in rats with short bowel syndrome (SBS) and to study its mechanism.</p><p><b>METHODS</b>SD rats were randomly assigned to three groups: sham rats (Con), SBS rats (SB) and SBS rats supplemented with enteral arginine (SB-Arg). All the animals received isonitrogenic and isocaloric enteral nutrition, except that SB-Arg rats received enteral nutrition supplemented with arginine (300 mg kg(-1) d(-1)). Fat absorbability, plasma free fatty acids, parameters of intestinal adaptation, enterocytes proliferation and apoptosis were determined.</p><p><b>RESULTS</b>After massive small bowel resection, rats had significant bowel adaptation. Compared with SB rats, SB-Arg rats demonstrated a significant increase in fat absorbability [(84.9+/-3.2)% vs [(81.3+/-3.9)%], plasma level of free fatty acids [(650.0+/-86.5) vs (289.5+/-76.9) mg/L], ileal mucosal weight [(18.0+/-3.5) vs (13.5+/-3.0) mg cm(-1) 100 g(-1)], ileal DNA content [(29.6+/-3.3) vs (26.0+/-2.6) microg cm(-1) 100 g(-1)], jejunal mucosal protein content [(65.5+/-7.3) vs (59.8+/-6.2) microg cm(-1) 100 g(-1)], ileal mucosal protein content[(39.2+/-2.3) vs(35.4+/-2.3) microg cm(-1) 100 g(-1)], jejunal mucosal proliferation index [31+/-4 vs 22+/-3] and ileal mucosal proliferation index [32+/-2 vs 25+/-3] (all P<0.05). Moreover, jejunal and ileal villus length, crypt depth and mucosal thickness in SBS-Arg rats were higher than those in SB rats (P<0.05).</p><p><b>CONCLUSIONS</b>In rat SBS model, enteral supplement of arginine appears to stimulate intestinal structural and functional adaptation. The mechanism may be that arginine can stimulate enterocyte proliferation and inhibit enterocyte apoptosis.</p>

Maintenance effect of polyglycosides of Tripterygium wilfordii on remission in postoperative Crohn disease / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To observe the maintenance effect of polyglycosides of Tripterygium wilfordii (GTW) on remission in postoperative Crohn disease (CD).</p><p><b>METHODS</b>From 2005 to 2007, 45 adult cases of postoperative Crohn disease were randomly divided into two groups, GTW group and mesalazine group, which received GTW and mesalazine treatment respectively. CD activity index (CDAI) and clinical markers were collected at 0, 3, 6, 12 months or at the onset of symptoms. Ileocolonoscopy was performed at the end of the trial (1 year after operation) or at the onset of symptoms, and recurrence score were recorded.</p><p><b>RESULTS</b>No clinical recurrence was ascertained in both groups at 3 months. Four patients (18.2%) in GTW group relapsed and 5 (21.7%) in mesalazine group relapsed at 6 months (P=0.530). Seven patients (31.8%) in GTW group and 9 (39.1%) in mesalazine group relapsed at one year (P=0.421). Ten patients (45.5%) in GTW group had endoscopic recurrence compared with 14 (60.9%) in mesalazine group at one year(P=0.231). There were no significant differences between two groups.</p><p><b>CONCLUSION</b>GTW is similar to mesalazine in maintenance of remission of postoperative Crohn disease.</p>