Metformin Affects Cardiac Arachidonic Acid Metabolism and Cardiac Lipid Metabolite Storage in a Prediabetic Rat Model

Metformin can reduce cardiovascular risk independent of glycemic control. The mechanisms behind its non-glycemic benefits, which include decreased energy intake, lower blood pressure and improved lipid and fatty acid metabolism, are not fully understood. In our study, metformin treatment reduced myocardial accumulation of neutral lipids—triglycerides, cholesteryl esters and the lipotoxic intermediates—diacylglycerols and lysophosphatidylcholines in a prediabetic rat model (p < 0.001). We observed an association between decreased gene expression and SCD-1 activity (p < 0.05). In addition, metformin markedly improved phospholipid fatty acid composition in the myocardium, represented by decreased SFA profiles and increased n3-PUFA profiles. Known for its cardioprotective and anti-inflammatory properties, metformin also had positive effects on arachidonic acid metabolism and CYP-derived arachidonic acid metabolites. We also found an association between increased gene expression of the cardiac isoform CYP2c with increased 14,15-EET (p < 0.05) and markedly reduced 20-HETE (p < 0.001) in the myocardium. Based on these results, we conclude that metformin treatment reduces the lipogenic enzyme SCD-1 and the accumulation of the lipotoxic intermediates diacylglycerols and lysophosphatidylcholine. Increased CYP2c gene expression and beneficial effects on CYP-derived arachidonic acid metabolites in the myocardium can also be involved in cardioprotective effect of metformin.

Effects of constant and diel cyclic temperatures on the liver and intestinal phospholipid fatty acid composition in rainbow trout Oncorhynchus mykiss during seawater acclimation

Background Rainbow trout is an economically important fish in aquaculture and is a model species in environmental physiology. Despite earlier research on the seawater adaptability of rainbow trout at different temperature regimes, the influence on the liver and intestine in this species is still unknown. Two trials were conducted to investigate the effects of constant and diel cyclic temperatures on phospholipid fatty acid (PLFA) composition in the liver and intestine of rainbow trout during seawater acclimation. Results At the end of growth trial 1, fish at 9 and 12.5 °C showed significantly higher ratios of unsaturated to saturated (U/S) and unsaturation index (UI) than those at 16 °C in liver and intestine phospholipids. After day 1 of seawater acclimation, the U/S, UI, and average chain length (ACL) of liver and intestinal phospholipids in fish at 16 °C significantly increased. Two weeks after seawater acclimation, the liver and intestinal PLFA composition adapted to salinity changes. In trial 2, significantly higher U/S, UI, and ACL were found in intestinal phospholipids at 13 ± 2 °C. On the first day after seawater acclimation, UI and ACL in liver phospholipids significantly increased at 13 °C, while fish at 13 ± 2 °C showed significantly decreased U/S, UI, and ACL in the intestine. At the end of growth trial 2, liver PLFA compositions were stable, whereas intestinal PLFA at 13 and 13 ± 1 °C showed significantly decreased U/S, UI, and ACL. A two-way analysis of variance and principal component analysis revealed significant effects of different constant temperatures, seawater acclimation, and their interaction on the liver and intestinal phospholipids, a significant effect of diel cyclic temperature on intestinal phospholipids, and the effects of seawater acclimation and its interaction with diel cyclic temperature on liver phospholipids. Conclusion Temperatures of 9 and 12.5 °C could elevate membrane fluidity and thickness in the liver and intestine of rainbow trout in freshwater, whereas no significant effects were found with diel temperature variations. After seawater acclimation, constant and diel cyclic temperatures significantly influenced the membrane fluidity and thickness of the liver and intestine. Compared with constant temperature, diel temperature variation (13 ± 2 °C) can enhance the adaptability of rainbow trout during seawater acclimation.

Effects of Constant and Diel Cyclic Temperatures on The Liver and Intestinal Phospholipid Fatty Acid Composition in Rainbow Trout Oncorhynchus Mykiss During Seawater Acclimation

Background: Rainbow trout is an important economic fish in aquaculture and a model species in environmental physiology. Despite of earlier research on the seawater adaptability of rainbow trout at different temperature regimes, the influence on liver and intestine in this species is still unknown. Two trials were conducted to investigate the effects of constant and diel cyclic temperatures on phospholipid fatty acid (PLFA) composition in the liver and intestine of rainbow trout during seawater acclimation.Results: At the end of the growth trial 1, fish at 9 and 12.5°C showed significantly higher ratios of unsaturated to saturated (U/S) and unsaturation index (UI) than those at 16°C in liver and intestine phospholipids. After day 1 of seawater acclimation, the U/S, UI, and average chain length (ACL) of liver and intestine phospholipids in fish at 16°C significantly increased. Two weeks after seawater acclimation, liver and intestinal PLFA composition adapted to salinity change. In trial 2, significantly higher U/S, UI, and ACL were found in intestinal phospholipids at 13±2°C. On the first day after seawater acclimation, UI and ACL in liver phospholipids significantly increased in 13°C, while fish in 13±2°C showed significantly decreased U/S, UI, and ACL in the intestine. At the end of the growth trial 2, liver PLFA compositions were stable, whereas intestinal PLFA in 13 and 13±1°C showed significantly decreased U/S, UI, and ACL. A two-way analysis of variance and principal component analysis revealed significant effects of different constant temperatures, seawater acclimation, and their interaction on the liver and intestinal phospholipids, a significant effect of diel cyclic temperature on intestinal phospholipids, and the effects of seawater acclimation and its interaction with diel cyclic temperature on liver phospholipids.Conclusion: Temperatures of 9 and 12.5°C could elevate membrane fluidity and thickness in the liver and intestine of rainbow trout in freshwater, whereas no significant effects were found with diel temperature variations. After seawater acclimation, constant and diel cyclic temperatures significantly influenced the liver and intestine's membrane fluidity and thickness. Compared with constant temperature, diel temperature variation (13±2°C) can enhance the adaptability of rainbow trout during seawater acclimation.

Effect of long-term strenuous training on the plasma phospholipid fatty acid composition in handball players

Background/Aim. Consensus on the exercise effect on the fatty acid metabolism has not been reached, and probably depends on the type of sports (aerobic, anaerobic or mixed). The aim of this study was to investigate effect of long-term handball training on the body composition, lipid profile and the plasma phospholipid fatty acid composition in female and male younger players. Methods. Seventeen female and 15 male active handball players, aged 16?20 years, who competed at the national/international level, were enrolled in the study. A control group was established from healthy, sedentary individuals (13 females and 19 males, aged 17?21 years), comparable to the athletes in terms of age, sex and body mass index. Results. In both groups of handball players a higher percentage of palmitoleic acid and alpha linolenic acid (18:3, n-3), were found and lower percentage of oleic acid and docosahexaenoic acid (22:6, n-3), when compared with corresponding control group. On the other hand, the lower level of stearic acid and estimated activity of plasma elongase was detected in female players than in sedentary women. Furthermore, higher proportion of linoleic acid (18:2, n-6), n-6 polyunsaturated fatty acids (PUFA) and total PUFA was found only in female players in comparison to the control group. Conclusion. The observed differences between handball players and sedentary individuals showed that handball training influenced lipid and fatty acid metabolism. Follow-up of these changes could indicate potential need for supplementation or nutritional intervention in young handball players.