AIM： TO investigate the effects of the somatostatin analogue, octreotide, on maltose and sucrase activities and expression of glucose transporter type 2 （GLUT2） in obese rat intestinal mucosa. METHODS： We divided ...AIM： TO investigate the effects of the somatostatin analogue, octreotide, on maltose and sucrase activities and expression of glucose transporter type 2 （GLUT2） in obese rat intestinal mucosa. METHODS： We divided 49 Sprague-Dawley rats into a group of 31 high fat diet-induced obese rats and a group of 18 normal controls. The obese rats were separated into an octreotide treated group 9f 16 rats and an obese group of 15. The intervention （：jroup was injected with octreotide at 40 ±g/kg body weight every 12 h for 8 d. Rat body weight was measured weekly to calculate Lee＇s index. After euthanization, maltase and sucrase activities in the small intestine were measured by activity assays, and the fasting plasma glucose level was measured. The expression of GLUT2 in small intestinal mucosa was analyzed by immunohistochemistry, reverse transcriptase polymerase chain reaction and Western blotting assays. RESULTS： Body weight, Lee＇s index, fasting plasma glucose level, maltase activity in small intestinal mucosa, mucosa and apical GLUT2, GLUT2 mRNA and protein expression levels were all significantly higher in the obese group than in the normal control group （605.61 ± 141.00 vs 378.54 ±111.75, 337.61 ± 10.82 vs 318.73 ± 20.10, 8.60± 1.38 vs 7.33 ± 0.70, 156.01 ± 58.81 vs 50.43 ± 30.49, 390 744.2± 62 469.21 vs 170 546.50 ± 50 646.14, 26 740.18 ±3809.60 vs 354.98± 57.19, 0.26± 0.11 vs 0.07± 0.02, and 2.08 ± 0.59 vs 1.27 ± 0.38, respectively, all P 〈 0.01）. Sucrase activity did not differ between the two groups. Octreotide intervention significantly decreased the body weight and fasting plasma glucose level of obese rats （508.27 ± 94.39 vs 605.61 ± 141.00, 7.58 ± 1.51 vs 8.60±1.38, respectively, all P 〈 0.05）. The intestinal mucosa and apical GLUT2, expression of GLUT2 mRNA and protein were also significantly lower in the octreotide intervention group than in the obese group （269 975.2 ± 53 730.94 vs 390 744.2 ± 62 469.21, 3758.06 ± 364.51 vs 26 740.18 ± 3809.60, 0.08 ± 0.02 vs 0.26 ±0.11, and 1.31 ± 0.27 vs 2.08 ±0.59, respectively, all P 〈 0.01）. CONCLUSION： High fat dietinduced obesity is associated with elevated intestinal maltase activity, GLUT2 expression, and permanent apical GLUT2 in the small intestinal mucosa of rats. Octreotide can inhibit these effects.展开更多
Quantification of hepatic fat and iron content is important for early detection and monitoring of nonalcoholic fatty liver disease(NAFLD) patients. This study evaluated quantification efficiency of hepatic proton dens...Quantification of hepatic fat and iron content is important for early detection and monitoring of nonalcoholic fatty liver disease(NAFLD) patients. This study evaluated quantification efficiency of hepatic proton density fat fraction(PDFF) by MRI using NAFLD rabbits. R2* was also measured to investigate whether it correlates with fat levels in NAFLD. NAFLD rabbit model was successfully established by high fat and cholesterol diet. Rabbits underwent MRI examination for fat and iron analyses,compared with liver histological findings. MR examinations were performed on a 3.0 T MR system using multi-echo 3 D gradient recalled echo(GRE) sequence. MRI-PDFF showed significant differences between different steatosis grades with medians of3.72%(normal), 5.43%(mild), 9.11%(moderate) and 11.17%(severe), whereas this was not observed in R2*. Close correlation between MRI-PDFF and histological steatosis was observed(r=0.78, P=0.000). Hepatic iron deposit was not found in any rabbits. There was no correlation between R2* and either liver MRI-PDFF or histological steatosis. MR measuring MRI-PDFF and R2* simultaneously provides promising quantification of steatosis and iron. Rabbit NAFLD model confirmed accuracy of MRI-PDFF for liver fat quantification. R2* measurement and relationship between fat and iron of NAFLD liver need further experimental investigation.展开更多
基金Supported by Grants from the National Natural Sciences Foundation of China,No.30870919Sichuan Provincial Department of Science and Technology,No.2010SZ0176
文摘AIM： TO investigate the effects of the somatostatin analogue, octreotide, on maltose and sucrase activities and expression of glucose transporter type 2 （GLUT2） in obese rat intestinal mucosa. METHODS： We divided 49 Sprague-Dawley rats into a group of 31 high fat diet-induced obese rats and a group of 18 normal controls. The obese rats were separated into an octreotide treated group 9f 16 rats and an obese group of 15. The intervention （：jroup was injected with octreotide at 40 ±g/kg body weight every 12 h for 8 d. Rat body weight was measured weekly to calculate Lee＇s index. After euthanization, maltase and sucrase activities in the small intestine were measured by activity assays, and the fasting plasma glucose level was measured. The expression of GLUT2 in small intestinal mucosa was analyzed by immunohistochemistry, reverse transcriptase polymerase chain reaction and Western blotting assays. RESULTS： Body weight, Lee＇s index, fasting plasma glucose level, maltase activity in small intestinal mucosa, mucosa and apical GLUT2, GLUT2 mRNA and protein expression levels were all significantly higher in the obese group than in the normal control group （605.61 ± 141.00 vs 378.54 ±111.75, 337.61 ± 10.82 vs 318.73 ± 20.10, 8.60± 1.38 vs 7.33 ± 0.70, 156.01 ± 58.81 vs 50.43 ± 30.49, 390 744.2± 62 469.21 vs 170 546.50 ± 50 646.14, 26 740.18 ±3809.60 vs 354.98± 57.19, 0.26± 0.11 vs 0.07± 0.02, and 2.08 ± 0.59 vs 1.27 ± 0.38, respectively, all P 〈 0.01）. Sucrase activity did not differ between the two groups. Octreotide intervention significantly decreased the body weight and fasting plasma glucose level of obese rats （508.27 ± 94.39 vs 605.61 ± 141.00, 7.58 ± 1.51 vs 8.60±1.38, respectively, all P 〈 0.05）. The intestinal mucosa and apical GLUT2, expression of GLUT2 mRNA and protein were also significantly lower in the octreotide intervention group than in the obese group （269 975.2 ± 53 730.94 vs 390 744.2 ± 62 469.21, 3758.06 ± 364.51 vs 26 740.18 ± 3809.60, 0.08 ± 0.02 vs 0.26 ±0.11, and 1.31 ± 0.27 vs 2.08 ±0.59, respectively, all P 〈 0.01）. CONCLUSION： High fat dietinduced obesity is associated with elevated intestinal maltase activity, GLUT2 expression, and permanent apical GLUT2 in the small intestinal mucosa of rats. Octreotide can inhibit these effects.
文摘Quantification of hepatic fat and iron content is important for early detection and monitoring of nonalcoholic fatty liver disease(NAFLD) patients. This study evaluated quantification efficiency of hepatic proton density fat fraction(PDFF) by MRI using NAFLD rabbits. R2* was also measured to investigate whether it correlates with fat levels in NAFLD. NAFLD rabbit model was successfully established by high fat and cholesterol diet. Rabbits underwent MRI examination for fat and iron analyses,compared with liver histological findings. MR examinations were performed on a 3.0 T MR system using multi-echo 3 D gradient recalled echo(GRE) sequence. MRI-PDFF showed significant differences between different steatosis grades with medians of3.72%(normal), 5.43%(mild), 9.11%(moderate) and 11.17%(severe), whereas this was not observed in R2*. Close correlation between MRI-PDFF and histological steatosis was observed(r=0.78, P=0.000). Hepatic iron deposit was not found in any rabbits. There was no correlation between R2* and either liver MRI-PDFF or histological steatosis. MR measuring MRI-PDFF and R2* simultaneously provides promising quantification of steatosis and iron. Rabbit NAFLD model confirmed accuracy of MRI-PDFF for liver fat quantification. R2* measurement and relationship between fat and iron of NAFLD liver need further experimental investigation.
