Influence of n-3 fatty acids on blood lipids in normal subjects. Journal oflnternal Medicine 1989: 225. Suppl. 1 : 99-104.The effects of consuming oils providing alpha-linolenic (ALA). eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids were studied in healthy volunteers. A blunted increase in plasma triglyceride was observed in subjects given a test meal containing fish oil compared with olive oil: cholesterol concentrations were not increased: increases in EPA and DHA were seen in all lipid fractions. In longer term supplementation studies, ALA increased EPA. but not DHA in plasma phospholipids : preformed EPA was more effective.The proportion of EPA in platelet lipids increased in a dose dependent manner. EPA or DHA. but not ALA. decreased plasma triglyceride and VLDL cholesterol concentrations. Supplements containing DHA increased HDL and HDL, cholesterol and LDL apoB. Total cholesterol and LDL cholesterol concentrations were unaltered.
Objectives:Vitamin B12 (B12) deficiency after Roux-en-Y gastric bypass (RYGB) is highly prevalent and may contribute to postoperative complications. Decreased production of intrinsic factor owing to gastric fundus removal is thought to have a major role, but other components of B12 metabolism may also be affected. We evaluated changes in the expression levels of multiple B12 pathway-encoding genes in gastrointestinal (GI) tissues to evaluate the potential roles in contributing to post-RYGB B12 deficiency.Methods:During double-balloon enteroscopy, serial GI biopsies were collected from 20 obese women (age, 46.9±6.2 years; body mass index, 46.5±5.3 kg/m2) with adult-onset type 2 diabetes (fasting plasma glucose ≥126 mg/dl; hemoglobin A1c≥6.5%) before and, at the same site, 3 months after RYGB. Gene expression levels were assessed by the Affymetrix Human GeneChip 1.0 ST microarray. Findings were validated by real-time quantitative PCR (RT–qPCR).Results:Gene expression levels with significant changes (P≤0.05) included: transcobalamin I (TCN1) in remnant (−1.914-fold) and excluded (−1.985-fold) gastric regions; gastric intrinsic factor (GIF) in duodenum (−0.725-fold); and cubilin (CUBN) in duodenum (+0.982-fold), jejunum (+1.311-fold), and ileum (+0.685-fold). Validation by RT–qPCR confirmed (P≤0.05) observed changes for TCN1 in the remnant gastric region (−0.132-fold) and CUBN in jejunum (+2.833-fold).Conclusions:RYGB affects multiple pathway-encoding genes that may be associated with postoperative B12 deficiency. Decreased TCN1 levels seem to be the main contributing factor. Increased CUBN levels suggest an adaptive genetic reprogramming of intestinal tissue aiming to compensate for impaired intestinal B12 delivery.
Roux-en-Y gastric bypass (RYGB) limits food ingestion and may alter the intestinal expression of genes involved in the endogenous synthesis of polyunsaturated fatty acids (PUFAs). These changes may decrease the systemic availability of bioactive PUFAs after RYGB. AIM: To study the impact of RYGB on the dietary ingestion and plasma concentration of PUFAs and on the intestinal expression of genes involved in their endogenous biosynthesis in severely obese women with type 2 diabetes. METHODS: Before, and 3 and 12 months after RYGB, obese women (n=20) self-reported a seven-day dietary record, answered a food frequency query and provided plasma samples for alpha-linolenic (ALA), eicosapentaenoic (EPA), docosahexaenoic (DHA) and arachidonic (ARA) acid assessment by gas chromatography. Intestinal biopsies (duodenum, jejunum and ileum) were collected through double-balloon endoscopy before and 3 months after RYGB for gene expression analysis by microarray (Human GeneChip 1.0 ST array) and RT-qPCR validation. RESULTS: Compared to the preoperative period, patients had decreased intakes of PUFAs, fish and soybean oil (p<0.05) and lower plasma concentrations of ALA and EPA (p<0.001) 3 and 12 months after RYGB. FADS1 gene expression was lower in duodenum (RT-qPCR fold change=-1.620, p<0.05) and jejunum (RT-qPCR fold change=-1.549, p<0.05) 3 months following RYGB, compared to before surgery. CONCLUSION: RYGB decreased PUFA ingestion, plasma ALA and EPA levels, and intestinal expression of FADS1 gene. The latter encodes a key enzyme involved in endogenous biosynthesis of PUFAs. These data suggest that supplementation of omega-3 PUFAs may be required for obese patients undergoing RYGB.
1 The biphasic (relaxation-contraction) response of the isolated duodenum was used to study the reactivity of non-vascular smooth muscles in genetic (SHR) and renal hypertensive rats compared to their respective controls (WKY and Wistar). 2 For the contractile component of the response to bradykinin, the duodenum from WKY rats was more sensitive, whereas the duodenum from SHR was both more sensitive and hyperreactive, compared to that from Wistar rats. 3 The relaxant component of the response to bradykinin was present in the duodenum of both WKY rats and SHR, but was concentration-dependent only in the WKY group. 4 The relaxant response to K+ was very small in SHR, and was not concentration-dependent. 5 The concentration-response curves for relaxant responses to adrenaline and for contractile responses to acetylcholine did not differ in the SHR and WKY groups. 6 Ca2+/Mg2+-ATPase activity was found to be markedly reduced in the SHR group. 7 No qualitative or quantitative differences were observed between the responses of the duodenum of renal hypertensive rats and those of their normotensive controls. 8 It is proposed that the altered reactivity of the SHR duodenum is due to changes in ion handling by the smooth muscle cell membrane.
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