The effect of antibiotics on hepatic lipid metabolism following small bowel bypass

To evaluate the hypothesis that hepatic lipid accumulation following small intestinal bypass may be related to bacterial overgrowth in the defunctionalized small bowel, hepatic lipid metabolism was evaluated in rats with small intestinal bypass treated and not treated with antibiotics. Small bowel bypass in nutritionally obese rats decreased body weight and food intake when compared to sham-operated controls. Antibiotic-treated rats ate less than did the rats not receiving antibiotics. Small intestinal bypass did not increase hepatic lipid accumulation in no-antibiotic treated rats. The small intestinal bypass rats receiving antibiotics had less total hepatic lipid and less hepatic triglyceride than did sham-operated controls and less hepatic lipid than did the rats not receiving antibiotics. Decreasing the bacterial population of the defunctionalized small bowel is associated with changes in hepatic lipid metabolism in rats with small bowel bypass. These changes may be produced by alterations in nutrient intake or by elimination of a “toxic” substance produced by small bowel bacterial overgrowth.     

Effects of Roux-en-Y gastric bypass and ileal transposition surgeries on glucose and lipid metabolism in skeletal muscle and liver

BackgroundRoux-en Y gastric bypass (RYGB) and ileal transposition (IT) surgeries produce weight loss and improve diabetic control; however, the mechanisms of glycemic improvements are largely unknown. Because skeletal muscle and liver play a key role in glucose homeostasis, we compared the effects of RYGB and IT surgeries on key molecules of glucose and lipid metabolism in muscle and liver.MethodsSprague-Dawley rats were subjected to RYGB, IT, or sham surgeries; sham-animals were ad-lib fed or pair-fed to RYGB rats (n = 7-9/group). At 8 weeks postoperatively, blood samples were collected for glucagon-like peptide-1 (GLP-1) and insulin analyses by ELISA. Leg muscle and liver tissues were analyzed for mRNA (RT-qPCR) and/or protein abundance (immuno blotting) of important molecules of glucose and lipid metabolism [glucose transporter-4 (GLUT-4), hexokinase, phosphofructokinase (PFK), adenosine monophosphate activated protein kinase-α (AMPKα), cytochrome C oxidase-IV (COX-IV), citrate synthase, carnitine palmitoyl transferase-1 (CPT-1), medium-chain acyl-CoA dehydrogenase (MCAD), peroxisome proliferator-activated receptor gamma co-activator 1 α (PGC-1 α), PGC-1-related coactivator (PRC), uncoupling protein-3 (UCP-3)].ResultsPlasma GLP-1 concentrations were increased comparably with RYGB and IT. RYGB and IT increased muscle GLUT-4 protein content, muscle hexokinase mRNA, and liver PFK mRNA. IT increased muscle AMPKα and COX-IV protein content and liver citrate synthase activity. IT increased muscle CPT-1, MCAD and PRC mRNA, whereas RYGB increased UCP-3 mRNA in muscle and liver, and PGC-1 α mRNA in liver.ConclusionThe data suggest that RYGB and IT surgeries lead to enhanced GLP-1 secretion and produce similar stimulatory effects on important molecules of glucose metabolism but differential effects on key molecules of lipid oxidation in muscle and liver.     

Bile salt metabolism following jejunoileal bypass for morbid obesity.

Bile salt pool size and kinetics were evaluated in 8 morbidly obese women before and following jejunoileal bypass. The results indicate that following jejunoileal bypass pool sizes of both chenodeoxycholate and cholate decrease, turnover rates increase, and the rates of bile salt synthesis increase. Influenced by pool size, hepatic synthesis and the degree of malabsorption, the daily bile salt loss may actually decrease in time. Chenodeoxycholate is more efficiently absorbed than cholate in both the preoperative and postoperative states. In spite of greater cholate synthetic capabilities, in this malabsorptive state the chenodeoxycholate pool decreases less than the cholate pool. Although all patients received an identical surgical procedure, the effect on bile salt kinetics and pool sizes varied in these patients. Since some of the postoperative complications may be related to the degree of interference with bile salt metabolism, the individual patient's capacity for increased hepatic synthesis of bile salts and increased reabsorption of bile salts from the remaining small bowel may vary the clinical postoperative course.     

袖状胃切除间置回肠的十二指肠空肠旁路手术对非肥胖性2型糖尿病患者脂质代谢的影响

目的评价袖状胃切除间置回肠的十二指肠空肠旁路手术对非肥胖性2型糖尿病患者脂质代谢的影响。方法回顾性分析2009年3月至2010年8月间在四川省攀枝花市中心医院接受袖状胃切除间置回肠的十二指肠空肠旁路手术的29例非肥胖型2型糖尿病患者的临床资料。术后12个月检测总胆固醇、三酰甘油、高密度脂蛋白、低密度脂蛋白、胰岛素抵抗指数及糖化血红蛋白（HbAlc）的变化。结果术后12个月时,28例（96．5％）患者血糖得到控制,无需服降糖药,HbAlc从术前的（8．4±1．3）％降至术后的（6．2±0．8）％,另1例血糖亦获改善。25例（86．2％）患者脂质代谢紊乱得到纠正,其中19例术前高胆固醇血症患者中16例（84．2％）术后恢复正常,17例高三酰甘油血症患者中14例（82.3％）恢复正常,12例高密度脂蛋白异常患者中8例（66．6％）恢复正常,16例低密度脂蛋白异常的患者中5例（31．2％）恢复正常;总胆固醇／高密度脂蛋白从术前的5．6±1．2降至术后的2．8±1．0,三酰甘油／高密度脂蛋白从术前的3．2±1.3降至术后的1．5±0．8（均P〈0．01）。结论袖状胃切除间置回肠的十二指肠空肠旁路手术能有效地改善非肥胖型2型糖尿病患者的脂质代谢紊乱。     

Effects of pulsatile cardiopulmonary bypass on carbohydrate and lipid metabolism

The influence of pulsatile perfusion on carbohydrate and lipid metabolism was examined in 40 patients (20 pulsatile and 20 non-pulsatile) who underwent open-heart surgery. The pulsatile assist device was used for pulsatile cardiopulmonary bypass during aortic cross-clamping only, and samples of the mixed venous blood were taken every 20 minutes. There were no statistically significant differences between pulsatile and non-pulsatile groups with respect to plasma levels of glucose, insulin, glucagon, free fatty acids and ketone bodies. However, an increase in the plasma level of noradrenaline was significantly suppressed in the pulsatile group, and triglyceride levels were significantly higher in the pulsatile than in the non-pulsatile group. These data suggest that pulsatile flow attenuates the catecholamine stress response to cardiopulmonary bypass and has a protective effect on liver function during bypass.     

Treatment of familial hypercholesterolaemia by partial ileal bypass.

Ten patients with heterozygous familial hypercholesterolaemia (Fredrickson type II) were treated by the operation of partial ileal bypass. Postoperatively, serum cholesterol levels fell by an average of 34% (P less than 0.005), and the decrease was satisfactorily sustained over a period of 12-30 months. Angina and xanthomas also improved in some patients. Postoperatively all patients experienced considerable diarrhoea, which lessened with time. Other complications of surgery included abdominal distension and cramps, colonic dilatation, sepsis and intestinal obstruction. It is concluded that partial ileal bypass significantly lowers serum cholesterol levels, but that in view of the complications the operation should be offered only to carefully selected patients who are intolerant of or unresponsive to conservative measures.     

Outcome following bypass, and proximal and distal ligation of popliteal aneurysms

BACKGROUND: The aim of this study was to describe early and late results of proximal and distal ligation for popliteal aneurysm (PA), combined with bypass, with particular reference to the fate of the excluded aneurysm. METHODS: Of a cohort of 116 patients with PAs, 66 were treated with bypass and ligation. Graft patency was determined by duplex surveillance. In addition, 17 patients with bypassed PAs underwent a total of 33 duplex scans to determine flow within the aneurysm and change in size. RESULTS: For initially patent PAs, 3-, 5- and 8-year primary bypass graft patency was 78, 78 and 51 per cent respectively. These rates were not statistically significantly different from those following bypass for thrombosed PA, 3- and 5-year primary patency being 72 and 65 per cent respectively. No PA produced further symptoms after bypass and ligation. No flow was seen in any aneurysm at follow-up. Only one showed an increase in size. CONCLUSION: Proximal and distal ligation with bypass produced satisfactory long-term patency with good exclusion of the PA.     

Hepatic blood flow and metabolism.

The relationship between liver blood flow and hepatic metabolism remains unclear. An animal model as well as a methodology that permits simultaneous assessment of both of these functions are proposed. Several fractions of inspired oxygen were used to produce arterial oxygen levels commonly seen in clinical practice; these ranged from hyperoxemia to established hypoxemia. Over this range there were no considerable changes in transhepatic blood flow, but there were considerable changes in hepatic metabolism as shown by measurements of the hepatic parenchymal pH, transhepatic oxygen consumption, and lactic acid use. Of these, the parenchymal pH seems to be the most sensitive indicator of metabolic events.     

Esmarch's bandage technique in distal bypass surgery.

Esmarch's rubber bandage technique has been applied to 49 distal bypass surgeries in 46 patients during the past ten years. The primary and secondary patency rates at 5 years after femoro-tibial bypass surgery were 82% and 92%, respectively. This technique has the following advantages: (1) it minimizes surgical injury of the arterial wall because there is less dissection around the anastomotic site; (2) it decreases scar formation in the anastomotic area after surgery; (3) it maintains abundant muscular blood flow by preserving small branches to muscles, and (4) it provides a bloodless surgical field and easy handling for fine sutures without using vascular clamps. We consider that the avoidance of long circumferential dissection of the artery may play an important role in improving long-term patency in distal bypass surgery.     

胃旁路术对糖尿病大鼠糖脂代谢的影响

目的 观察Roux-en-Y胃旁路术对糖尿病Coto-Kakizaki(CK)大鼠糖脂代谢的影响.方法 18只GK大鼠随机等分为Roux-en-Y胃旁路手术组(RYGB组)、假RYGB组和对照组;观察手术后1、2、4、12周各组大鼠空腹血糖、C肽和体质量增加值变化,同时观察手术后4周、12周血浆糖化血红蛋白、甘油三酯、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇含量变化.结果 手术前3组大鼠各检测指标差异无统计学意义(P>0.05).手术后1、2、4、12周RYGB组大鼠空腹血糖(7.0±0.8比6.5±1.0比6.3±1.5比5.6±1.7比4.3±0.5,P<0.01)明显降低,空腹C肽(0.21±0.06比0.28±0.09比0.52±0.06比0.71±0.06比0.78±0.06,P<0.01)显著升高;手术后4、12周大鼠糖化血红蛋白(9.71±1.34比9.09±1.21比7.34±1.17,P<0.01)、甘油三酯(1.32±0.17比0.87±0.05比1.22±0.15,P<0.01)、低密度脂蛋白胆固醇(1.61±0.25比1.21±0.20比1.16±0.15,P<0.01)明显降低,高密度脂蛋白胆同醇(0.83±0.10比1.11±0.12比1.23±0.16,P<0.01)明显升高(P<0.01).各组大鼠体质量增加值差异均有统计学意义(P<0.05).假RYGB组和对照组其余各检测指标的变化差异均无统计学意义(P>0.05).结论 Roux-en-Y胃旁路术可改善非肥胖糖尿病GK大鼠血糖和血脂代谢,且与体质量变化无关.     

胃旁路术对糖尿病大鼠糖脂代谢的影响

Objective To observe the effects of gastric bypass on carbohydrate and lipid metabolism in Goto-Kakizaki (GK) type 2 diabetic rats. Methods Eighteen male GK rats were randomly divided into Roux-en-Y gastric bypass (RYGB) group, sham RYGB group (sham-RYGB) and pair-fed control group. Before and 1, 2, 4, 12 weeks after operation, the values of fasting glucose (FPG), weight gain and C-peptide (FC-P) were measured, and levels of glycosylated hemoglobin (GHbAlc) , triglycerides (TG) , high density lipoprotein (HDL-c) and low density lipoprotein (LDL-c) were determined before and 4, 12 weeks after operation. Results No significant differences were observed in pre-operative values (P>0. 05) among three groups. In RYGR group, serum levels measured before and 1, 2, 4, and 12 weeks after operation were as follows:FPG (7.0±0. 8 vs. 6. 5 ±1.0 vs. 6. 3±1. 5 vs. 5. 6±1. 7 vs. 4. 3±0.5, P<0.01), FC-P(0.21±0.06 vs. 0.28±0.09 vs. 0. 52±0. 06 vs. 0.71±0.06 vs. 0.78±0.06,P<0. 01) ;levels of GHbAlc (9. 71±1. 34 vs. 9. 09±1. 21 vs. 7. 34±1. 17,P<0. 01 ) , TG (1.32±0.17 vs. 0.87±0.05 vs. 1. 22±0.15,P <0.01), and LDL-c (1.61 ±0.25 vs. 1.21 ±0.20 vs. 1. 16 ±0.15,P<0.01), HDL-c (0.83 ±0.10 vs. 1.11 ±0.12 vs. 1.23 ±0. 16,P<0.01) before and 4, 12 weeks after operation. Weight gains had significant difference in each group before and after operation.In sham-RYGB and control groups, no significant differences were observed before and after operation in values of the other parameters. Conclusion Roux-en-Y gastric bypass can significantly regulate the metabolism of carbohydrate and lipid in GK rats, and the effects are not associated with weight gain.