Lipoprotein lipase activity in skeletal muscles of the rat: effects of denervation and tenotomy

Smol, Ewelina; ̇ernicka, E. Z; Czarnowski, D.; Langfort, Józef

doi:10.1152/jappl.2001.90.3.954

Cited by 9 publications

(7 citation statements)

References 36 publications

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“…In agreement with our laboratory's previous results (34), the present data showed that, in both the soleus and red portion of gastrocnemius muscles, the activity of the HLPL fraction is more affected by denervation than activity of the RLPL. This suggests that reduced LPL activity after the nerve crush may result from not only decreased synthesis of the enzyme but also restrained translocation of LPL particles to the plasma membrane and their reduced secretion from myocytes to capillaries.…”

Section: Discussionsupporting

confidence: 94%

“…Moreover, it was demonstrated previously that some enzymes display an "overshoot" activity, possibly reflecting increased energy demand by growing muscle (6). The increased LPL activity during progressive reinnervation, which accompanies increasing contractile activity of muscles, supports also the results of our laboratory's previous study, in which it was shown that enhanced contractile activity of denervated muscle by electrostimulation partly restored activities of both LPL fractions (34).…”

Section: Discussionsupporting

confidence: 82%

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Time course of changes in lipoprotein lipase activity in rat skeletal muscles during denervation-reinnervation

̇ernicka

Smol

Langfort

et al. 2002

Journal of Applied Physiology

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Ż ernicka, E., E. Smol, J. Langfort, and M. Gó recka. Time course of changes in lipoprotein lipase activity in rat skeletal muscles during denervation-reinnervation. J Appl Physiol 92: 535-540, 2002; 10.1152/japplphysiol.00820. 2001.-The effects of denervation-reinnervation after sciatic nerve crush on the activity of extracellular and intracellular lipoprotein lipase (LPL) were examined in the soleus and red portion of gastrocnemius muscles. The activity of both LPL fractions was decreased in the two muscles within 24 h after the nerve crush and remained reduced for up to 2 wk. During the reinnervation period, LPL activity was still reduced in the soleus and started to increase only on the 40th day. In the red gastrocnemius, LPL activity increased progressively with reinnervation, exceeding control values on the 30th day postcrush. The LPL activity in the soleus from the contralateral to denervated hindlimb was also affected, being increased on the postoperation day and then gradually decreased during the following days. In conclusion, the time course of changes in muscle LPL activity after nerve crush confirmed the predominant role of nerve conduction in controlling muscle potential to take up free fatty acids derived from the plasma triacylglycerols. However, other factors, such as muscle fiber composition and the fiber transformation, should also be considered in this aspect of the denervation-reinnervation process. Moreover, it was found that denervation of muscles from one hindlimb may influence LPL activity in muscles from the contralateral leg. skeletal muscle; denervation; reinnervation PERIPHERAL NERVE CRUSH leads to functional denervation of muscles with a variety of degenerative changes in muscle morphology and biochemistry that subsist until the regeneration of injured nerve takes place. The changes include an immediate loss of muscle activity followed by atrophy and degeneration of muscle fibers, a decrease in mitochondrial oxidative enzyme activities, and a fall in high-energy phosphate contents (6,8,21,38). Reinnervation and regeneration of skeletal muscles result in restoration, to some degree, of the original muscle fiber structure and contractile activity accompanied by a reversal of some previous biochemical alterations (8,12,24,25). The rate of recovery of metabolic alterations induced by denervation is different for enzymes of various metabolic pathways, and so it depends on the muscle fiber type (33, 38).Lipoprotein lipase (LPL) is a major enzyme responsible for hydrolysis of triacylglycerols (TG) derived from circulating TG-rich lipoproteins, making fatty acids available for cellular uptake. LPL in skeletal muscles, as in other tissues, is under a complex control by dietary and hormonal factors that modulate the enzyme activity at the cellular and molecular levels. In addition, LPL exhibits muscle fiber type-specific regulation that is closely related not only to the oxidative capacity of the muscle but also to its capability of replenishing the intramuscular TG stores (3,20). LPL activi...

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Section: Discussionsupporting

confidence: 94%

Section: Discussionsupporting

confidence: 82%

Time course of changes in lipoprotein lipase activity in rat skeletal muscles during denervation-reinnervation

̇ernicka

Smol

Langfort

et al. 2002

Journal of Applied Physiology

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“…For both type I and type II fibres, the cross-sectional area, activities of succinate dehydrogenase, and the capillary-to-fibre ratio are significantly reduced in paralyzed muscles . Moreover, the activity of the primary enzyme for conversion of circulating lipoprotein triglyceride into (membrane-permeable) free fatty acids, lipoprotein lipase (LPL), is decreased in denervated rat soleus muscle, supporting the concept that contractile activity is importantly involved in the regulation of the metabolic muscle phenotype (Smol et al 2001).…”

Section: Denervationmentioning

confidence: 86%

Molecular basis of skeletal muscle plasticity-from gene to form and function

Flück

Hoppeler

2003

Reviews of Physiology, Biochemistry and Pharmacology

370

334

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Skeletal muscle shows an enormous plasticity to adapt to stimuli such as contractile activity (endurance exercise, electrical stimulation, denervation), loading conditions (resistance training, microgravity), substrate supply (nutritional interventions) or environmental factors (hypoxia). The presented data show that adaptive structural events occur in both muscle fibres (myofibrils, mitochondria) and associated structures (motoneurons and capillaries). Functional adaptations appear to involve alterations in regulatory mechanisms (neuronal, endocrine and intracellular signalling), contractile properties and metabolic capacities. With the appropriate molecular techniques it has been demonstrated over the past 10 years that rapid changes in skeletal muscle mRNA expression occur with exercise in human and rodent species. Recently, gene expression profiling analysis has demonstrated that transcriptional adaptations in skeletal muscle due to changes in loading involve a broad range of genes and that mRNA changes often run parallel for genes in the same functional categories. These changes can be matched to the structural/functional adaptations known to occur with corresponding stimuli. Several signalling pathways involving cytoplasmic protein kinases and nuclear-encoded transcription factors are recognized as potential master regulators that transduce physiological stress into transcriptional adaptations of batteries of metabolic and contractile genes. Nuclear reprogramming is recognized as an important event in muscle plasticity and may be related to the adaptations in the myosin type, protein turnover, and the cytoplasma-to-myonucleus ratio. The accessibility of muscle tissue to biopsies in conjunction with the advent of high-throughput gene expression analysis technology points to skeletal muscle plasticity as a particularly useful paradigm for studying gene regulatory phenomena in humans.Structure, function: bOX b-Oxidation · DEL Deltoidus · EC coupling Excitationcontraction coupling · EDL Extensor digitorum longus · Gls Glycolysis · H+ Reducing equivalents · IMF mitochondria Interfibrillar mitochondria · IMCL Intra-myocellular lipid · KC Krebs cycle · M Muscle · NMJ Neuromuscular junction · SR Sarcoplasmic reticulum · S mitochondria Subsarcolemmal mitochondria · Tn Troponin · VL Vastus lateralis · VO2max Maximal oxygen consumption Signals, sensors and transducers: ACTH Corticotropin · AMPK 5'-AMP-activated protein kinase · ATP Adenosine 5'-triphosphate · Ca2+ Intracellular calcium · CaMKII Ca 2+ /CaM kinase II · Cor Cortisol · EN Epinephrine · ERK Extracellular signal-regulated kinase · GH Growth hormone · IGFBP-3 Insulin-like growth factor binding protein 3 · IGF-I Insulin-like growth factor I · JNK c-jun N-terminal kinase · c-jun cellular counterpart of retroviral insert from avian sarcoma virus 17 · Ins Insulin · lep Leptin · MAPK Mitogen-activated (microtubule-associated) protein kinase · NRF-1 and -2 Nuclear respiratory factor 1 and 2 · p38 p38 MAPK · RE Renin · ROS Reactive oxygen species · T3 Triiodothyron...

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“…According to some investigations, such alterations are due to the influence of physical exercise on the activity of the lipoprotein lipase enzyme, which is increased in the active individuals [31][32][33][34] . Classical studies show that decreased blood HDL-cholesterol levels increase the risk of developing coronary artheriosclerosis 35,36 .…”

Section: Discussionmentioning

confidence: 99%

Níveis de atividade física e alterações metabólicas em pessoas vivendo com HIV/AIDS

Romancini

Guariglia

Nardo

et al. 2012

Rev Bras Med Esporte

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The introduction of Highly Active Antiretroviral Therapy (HAART) has deeply changed the course of HIV infection with increase in survival and improvement in quality of life as well as partial restoration of the immune system. After about ten years from the HAART use, the effects of combination treatment / virus started to come out. Among these, we can mention changes in lipid metabolism with hypertriglyceridemia, hypercholesterolemia, insulin resistance, hyperglycemia and redistribution of body fat as risk factors for cardiovascular disease. Observational studies with people living with HIV / AIDS evidence that when an individual finds out that he/she is an HIV/AIDS patient, he/she end ups feeling fear or shame, reducing hence social circle, work and leisure activities, and becomes isolated at home or in small groups which have common identity of HIV / AIDS patients. The purpose of this work was to evaluate the relationship between the level of habitual physical activity and recreation of people living with HIV / AIDS and its relation with metabolic changes. The patients were classified into active and sedentary, using the Habitual Physical Activity questionnaire proposed by Baecke and validated for HIV / AIDS patients. Classification was conducted according to the recommendations of the American College of Sports Medicine. Metabolism was assessed through plasma levels of glucose, total cholesterol, HDL-cholesterol, LDL-cholesterol and triglycerides, using commercial kits. The sample consisted of 65 HIV patients who used HAART for at least five years. 64.6% were classified as sedentary and 35.4% as active. The study shows a direct relationship between physical activity level and higher levels of HDL -cholesterol in HIV / AIDS. HDL -Cholesterol is a lipoprotein of cardiovascular protection and, although other assessed parameters have not shown difference, these results highlight the need for additional studies on risk factors and physical activity for HIV / AIDS enabling proposals for specific interventions for these patients.

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Lipoprotein lipase activity in skeletal muscles of the rat: effects of denervation and tenotomy

Cited by 9 publications

References 36 publications

Time course of changes in lipoprotein lipase activity in rat skeletal muscles during denervation-reinnervation

Time course of changes in lipoprotein lipase activity in rat skeletal muscles during denervation-reinnervation

Molecular basis of skeletal muscle plasticity-from gene to form and function

Níveis de atividade física e alterações metabólicas em pessoas vivendo com HIV/AIDS

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