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Rodrigues 2020 J Appl Physiol (1985)

From Bioblast
Publications in the MiPMap
Rodrigues GC, Rocha NN, Maia LA, Melo I, Simões AC, Antunes MA, Bloise FF, Woyames J, da-Silva WS, Capelozzi VL, Abela G, Ball L, Pelosi P, Rocco PRM, Silva PL (2020) Impact of experimental obesity on diaphragm structure, function and bioenergetics. J Appl Physiol (1985) 129:1062-74.

» PMID: 32909923

Rodrigues Gisele C, Rocha Nazareth N, Maia Ligia A, Melo Isabella, Simoes Ana Carolina, Antunes Mariana A, Bloise Flavia F, Woyames Juliana, Seixas da-Silva Wagner, Capelozzi Vera Luiza, Abela Glenn, Ball Lorenzo, Pelosi Paolo, Rocco Patricia Rieken Macedo, Silva Pedro Leme (2020) J Appl Physiol (1985)

Abstract: Obesity is associated with bioenergetic dysfunction of peripheral muscles; however, little is known regarding the impact of obesity on the diaphragm. We hypothesized that obesity would be associated with diaphragm dysfunction attributable to mitochondrial oxygen consumption and structural and ultrastructural changes. Wistar rat litters were culled to 3 pups to induce early postnatal overfeeding and consequent obesity. Control animals were obtained from unculled litters. From postnatal day 150, diaphragm ultrasonography, computed tomography, high-resolution respirometry, immunohistochemical, biomolecular and ultrastructural histological analyses were performed. The diaphragms of obese animals, compared to those of controls, exhibited presented changes in morphology as increased thickening fraction, diaphragm excursion and diaphragm dome height, as well as increased mitochondrial respiratory capacity coupled to ATP synthesis and maximal respiratory capacity. Fatty acid synthase expression was also higher in obese animals, suggesting a source of energy for the respiratory chain. Myosin heavy chain-IIA was increased, indicating shift from glycolytic toward oxidative muscle fiber profile. Diaphragm tissue also exhibited ultrastructural changes, such as compact, round, and swollen mitochondria with fainter cristae and more lysosomal bodies. Dynamin-1 expression in the diaphragm was reduced in obese rats, suggesting decreased mitochondrial fission. Furthermore, gene expressions of peroxisome gamma proliferator-activated receptor co-activator-1α and superoxide dismutase-2 were lower in obese animals than in controls, which may indicate a predisposition to oxidative injury. In conclusion, in the obesity model used herein, muscle fiber phenotype was altered in a manner likely associated with increased mitochondrial respiratory capability, suggesting respiratory adaptation to increased metabolic demand. Keywords: Diaphragm, Function, Mitochondria, Obesity, Respiratory mechanics Bioblast editor: Plangger M

Labels: MiParea: Respiration  Pathology: Obesity 

Organism: Rat  Tissue;cell: Skeletal muscle  Preparation: Permeabilized tissue 

Coupling state: LEAK, OXPHOS, ET  Pathway: N, CIV, NS  HRR: Oxygraph-2k