Skeletal Muscle Characteristics of Rats with Obesity, Diabetes, Hypertension, and Hyperlipidemia

Nagatomo, Fumiko; Gu, Ning; Fujino, Hidemi; Takeda, Isao; Tsuda, Kinsuke; Ishihara, Akihiko

doi:10.5551/jat.1065

Cited by 33 publications

(64 citation statements)

References 43 publications

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“…Glycolytic EDL muscles rely more on glucose supply for their main source of energy and have lower rates of FA oxidation and lower insulin sensitivity than SOL muscles (46,49). In addition, mRNA expression of SCD1 was higher in SOL muscle from animal models in which the fiber types were shifted from high-oxidative toward low-oxidative fibers (38), and SCD activity of microsomes of fast-twitch muscle has been found to be lower than that of slow-twitch muscle (45). Therefore, it may be speculated that the high SCD1 expression in EDL muscles is related to the glucose metabolism and high palmitate levels (C16:0) in glycolytic muscles and to a compensation for the lower SCD activity of the sarcoplasmic reticulum membrane, thus allowing these muscles to deal with increased levels of SFAs.…”

Section: Discussionmentioning

confidence: 85%

The effect of dietary fat content on phospholipid fatty acid profile is muscle fiber type dependent

Janovská

Hatzinikolas

Mano

et al. 2010

American Journal of Physiology-Endocrinology and Metabolism

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IR has been linked to alterations and increased saturation in the phospholipid composition of skeletal muscles. We aimed to determine whether HFD feeding affects fatty acid (FA) membrane profile in a muscle fiber type-specific manner. We measured phospholipid FAs and expression of FA synthesis genes in oxidative soleus (SOL) and glycolytic extensor digitorum longus (EDL) muscles from rats fed either standard chow (standard laboratory diet, SLD) or a HFD. The HFD increased fat mass, plasma insulin, and leptin levels. Compared with EDL, SOL muscles preferentially accumulated C18 over C16 FAs and n-6 over n-3 polyunsaturated FAs (PUFAs) on either diet. With the HFD, SOL muscles contained more n-9 monounsaturated FAs (MUFAs) and n-6 PUFAs and less n-7 MUFAs and n-3 PUFAs than EDL muscles and had lower unsaturation index, a pattern known to be associated with IR. Stearoyl-CoA desaturase-1 expression was ϳ13-fold greater in EDL than in SOL muscles but did not change with the HFD in either muscle. The expression of Elongase-5 was higher, and that of Elongase-6 (Elovl6) was lower in EDL compared with SOL muscles with both diets. In EDL muscles, the expression of Elovl6 was lower in the HFD than in the SLD. The pattern of FA uptake, expression, and diet-induced changes in FA desaturating and elongating enzymes maintained higher FA unsaturation in EDL muscles. Accordingly, the fiber type composition of skeletal muscles and their distribution may be important in the development and progression of obesity and IR. skeletal muscle; stearoyl-coenzyme A desaturase; elongases; obesity HIGH-FAT DIET (HFD) feeding leads to obesity in rodents as well as in humans (15, 17) and, in skeletal muscles, to an increase in the intracellular content of lipids and resistance to the actions of insulin (IR) and leptin.Skeletal muscle represents 40 -50% of the total body mass and is the major tissue responsible for whole body insulinstimulated glucose disposal. Skeletal muscle fibers are divided into three major categories, types I, IIa, and IIb. Type I fibers are slow-twitch, oxidative (SO) fibers with a high mitochondrial content; type IIa fibers are fast-twitch, oxidative-glycolytic (FOG) fibers that are high in both mitochondrial and glycogenolytic enzymes; type IIb fibers are fast-twitch, glycolytic (FG) fibers that are high in the enzymes of glycogenolysis (22,59). Although the oxidative muscle fibers are highly dependent on lipids as a substrate, the glycolytic or oxidativeglycolytic fibers utilize either predominantly glucose or a fuel mixture with an important contribution of glucose as a substrate under normal feeding conditions (46). Oxidative muscles are more insulin sensitive and have a greater insulin binding capacity (5), kinase activity of insulin receptor (25), content of glucose transporter (GLUT)4 (26), and insulin-stimulated glucose uptake (35) than glycolytic muscles. In obesity and IR, the distribution of fiber types is shifted from oxidative toward glycolytic muscle fibers (21).In skeletal muscle, saturated fatty acids (S...

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Section: Discussionmentioning

confidence: 85%

The effect of dietary fat content on phospholipid fatty acid profile is muscle fiber type dependent

Janovská

Hatzinikolas

Mano

et al. 2010

American Journal of Physiology-Endocrinology and Metabolism

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“…On the other hand, many conditions, such as CVD risk factors, lead to alteration in skeletal muscles capillary support and may, consequently, impair the offer of oxygen and nutrients, which is related to alteration in the distribution of the skeletal muscle fiber types towards the increase of type II fibers. The origin of the transition from type I fibers to type II in soleus muscle of SHR still remains little known; however, studies show it is related to capillary rarefaction followed by alterations in the metabolic properties 11,28 . Studies show that, when there is a transition between the types of fibers of the skeletal muscle, the different morphological properties of the muscular fiber are changed in the following manner: the capillary density and the activities of the enzymes of the energetic metabolism are early altered during the transition and precede the change in the activity of the myofibrillar ATPase and the contractile characteristics of the muscle 8,29 .…”

Section: Discussionmentioning

confidence: 99%

“…In mammals, the fibers of the skeletal muscle are usually classified in type I and type II fiber according to the different activities of the myosin ATPase after the pre-incubation in different pHs, and the type II fibers can be subclassified in IIA, IIX/D and IIB. The type II fibers are characterized as being fast twitch with predominance of glycolytic metabolism, while the type I fibers are slow twitch ones with predominance of oxidative metabolism 11,30 . There is a lot of evidence in the literature shows that the skeletal muscle of hypertensive individuals, as well as of SHR, contains higher percentage of type II fast twitch, glycolytic fibers compared with their normotensive control [7][8][9][10][11] .…”

Section: Discussionmentioning

confidence: 99%

“…The type II fibers are characterized as being fast twitch with predominance of glycolytic metabolism, while the type I fibers are slow twitch ones with predominance of oxidative metabolism 11,30 . There is a lot of evidence in the literature shows that the skeletal muscle of hypertensive individuals, as well as of SHR, contains higher percentage of type II fast twitch, glycolytic fibers compared with their normotensive control [7][8][9][10][11] . Interestingly, the results obtained in the composition of the fiber types of the soleus skeletal muscle, the muscle investigates in this study, which presents an average of 90% of type I fibers and 10% of type II fibers, performed both by histochemical myosin ATPase reaction and SDS-PAGE gel electrophoresis for detection of myosins of heavy chain (MHC) for each type of fiber, were positively correlated regardless of the technique applied 10 .…”

Section: Discussionmentioning

confidence: 99%

“…Experimental and clinical studies show that dysfunction in the vasomotor tonus and alterations in the microvascular structure are the primary processes in the HTN pathogenesis [3][4][5][6] . Many studies have shown capillary rarefaction in the skeletal muscle of animals and hypertensive patients [3][4][5][6] , with increase in the percentage of fast twitch fibers, which present predominance of glycolytic metabolism 8,12 and classified as type II fibers [7][8][9][10][11] . The skeletal muscle presents high plasticity and suffers transition of fiber type due to the alterations in the isoforms of myosin of heavy chain (MHC) in many conditions, such as: disuse, growth, aging, electrical stimulus, exposure to microgravity, physical exercises and CVD 8,11 .…”

Section: Introductionmentioning

confidence: 99%

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O treinamento físico aeróbio corrige a rarefação capilar e as alterações nas proporções dos tipos de fibra muscular esquelética em ratos espontaneamente hipertensos

Fernandes

Roque

Magalhães

et al. 2012

Rev Bras Med Esporte

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Aerobic exercise training (ET) has been established as an important non-pharmacological treatment of hypertension, since it decreases blood pressure. Studies show that the skeletal muscle abnormalities in hypertension are directly associated with capillary rarefaction, higher percentage of fast-twitch fibers (type II) with glycolytic metabolism predominance and increased muscular fatigue. However, little is known about these parameters in hypertension induced by ET. We hypothesized that ET corrects capillary rarefaction, potentially contributing to the restoration of the proportion of muscle fiber types and metabolic proprieties. Twelve-week old Spontaneously Hypertensive Rats (SHR, n=14) and Wistar Kyoto rats (WKY, n=14) were randomly assigned into 4 groups: SHR, trained SHR (SHR-T), WKY and trained WKY (WKY-T). As expected, ten weeks of ET was effective in reducing blood pressure in SHR-T group. In addition, we analyzed the main markers of ET. Resting bradycardia, increase of exercise tolerance, peak oxygen uptake and citrate synthase enzyme activity in trained groups (WKY-T and SHR-T) showed that the aerobic condition was achieved. ET also corrected the skeletal muscle capillary rarefaction in SHR-T. In parallel, we observed reduction in percentage of type IIA and IIX fibers and simultaneous augmented percentage of type I fibers induced by ET in hypertension. These data suggest that ET prevented changes in soleus fiber type composition in SHR, since angiogenesis and oxidative enzyme activity increased are important adaptations of ET, acting in the maintenance of muscle oxidative metabolism and fiber profile.

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Beneficial effects of mangiferin on hyperlipidemia in high‐fat‐fed hamsters

Guo

Huang

Liao

et al. 2011

Molecular Nutrition Food Res

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Skeletal Muscle Characteristics of Rats with Obesity, Diabetes, Hypertension, and Hyperlipidemia

Cited by 33 publications

References 43 publications

The effect of dietary fat content on phospholipid fatty acid profile is muscle fiber type dependent

The effect of dietary fat content on phospholipid fatty acid profile is muscle fiber type dependent

O treinamento físico aeróbio corrige a rarefação capilar e as alterações nas proporções dos tipos de fibra muscular esquelética em ratos espontaneamente hipertensos

Beneficial effects of mangiferin on hyperlipidemia in high‐fat‐fed hamsters

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