scholarly journals 145 President Oral Presentation Pick: Prenatal stress increases skeletal muscle mitochondrial volume density and function in yearling Brahman calves

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 120-121
Author(s):  
Chloey P Guy ◽  
Catherine L Wellman ◽  
David G Riley ◽  
Charles R Long ◽  
Ron D Randel ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Creatine Kinase ◽  
Muscle Damage ◽  
Prenatal Stress ◽  
Citrate Synthase ◽  
Volume Density ◽  
Assembly Factor ◽  
Mitochondrial Volume ◽  
Mitochondrial Volume Density ◽  
And Function

Abstract We previously determined that prenatal stress (PNS) differentially affected methylation of DNA from leukocytes of 28-d-old calves. Specifically, COX14 (cytochrome c oxidase (COX) assembly factor) and CKMT1B (mitochondrial creatine kinase U-type) were hypomethylated and COA5 (COX assembly factor 5), COX5A (COX subunit 5A), NRF1 (nuclear respiratory factor 1), and GSST1 (glutathione S-transferase theta-1) were hypermethylated in PNS compared to non-PNS calves (P ≤ 0.05). Our current objective was to test the hypothesis that PNS exhibit impaired mitochondrial function and greater oxidative stress than non-PNS calves. Blood and longissimus dorsi muscle samples were collected from yearling Brahman calves whose mothers were stressed by 2 h transportation at 60, 80, 100, 120, and 140 days of gestation (PNS; 8 bulls, 6 heifers) and non-PNS calves (4 bulls, 6 heifers). Serum was evaluated for the stress hormone, cortisol, and muscle damage marker, creatine kinase; muscle was analyzed for mitochondrial volume density and function by citrate synthase (CS) and COX activities, respectively, concentration of malondialdehyde, a lipid peroxidation marker, and activity of the antioxidant, superoxide dismutase (SOD). Data were analyzed using mixed linear models with treatment and sex as fixed effects. Serum cortisol was numerically higher in PNS than non-PNS calves but was not statistically different. Muscle CS and COX activities relative to protein were greater in PNS than non-PNS calves (P ≤ 0.03), but COX relative to CS activity was similar between groups. Activity of COX was greater in bulls than heifers (P = 0.03), but no other measure was affected by sex. All other measures were unaffected by PNS. Prenatal stress did not affect markers of muscle damage and oxidative stress in yearling Brahman calves at rest but mitochondrial volume density and function were greater in PNS calves. Acute stressors induce oxidative stress, so implications of differences in mitochondria in PNS calves following a stressor should be investigated.

241 Skeletal Muscle Mitochondrial Capacities Are Impacted by Breed and Temperament in Young Angus and Brahman Steers

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 127-127
Author(s):  
Chloey P Guy ◽  
Lauren T Wesolowski ◽  
Audrey L Earnhardt ◽  
Dustin Law ◽  
Don A Neuendorff ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Fixed Effects ◽  
Linear Models ◽  
Citrate Synthase ◽  
Volume Density ◽  
Skeletal Muscle Mitochondria ◽  
Mitochondrial Volume ◽  
Mitochondrial Volume Density ◽  
Brahman Steers ◽  
The Impact

Abstract Temperament impacts skeletal muscle mitochondria in Brahman heifers, but this has not been investigated in steers or between cattle breeds. We hypothesized mitochondrial measures would be greater in Angus than Brahman, temperamental than calm steers, and the trapezius (TRAP) than the longissimus thoracis (LT) muscle. Samples from calm (n = 13 per breed), intermediate (n = 12 per breed), and temperamental (n=13 per breed) Angus and Brahman steers (mean±SD 10.0±0.8 mo) were evaluated for mitochondrial enzyme activities via colorimetry. Calm and temperamental LT samples were evaluated for oxidative phosphorylation (P) and electron transfer (E) capacities by high-resolution respirometry. Data were analyzed using linear models with fixed effects of breed, muscle, temperament, and all interactions. Brahman tended to have greater mitochondrial volume density (citrate synthase activity; CS) than Angus (P = 0.08), while intrinsic (relative to CS) mitochondrial function (cytochrome c oxidase activity) was greater in Angus than Brahman (P = 0.001) and greater in TRAP than LT (P = 0.008). Angus exhibited greater integrative (per mg tissue) and intrinsic P with complex I (PCI), P with complexes I+II (PCI+II), maximum noncoupled E, and E with complex II (ECII; P ≤ 0.04) and tended to have greater intrinsic leak (P = 0.1) than Brahman. Contribution of PCI to total E was greater in Angus than Brahman (P = 0.01), while contribution of ECII to total E was greater in Brahman than Angus (P = 0.05). A trend for the interaction of breed and temperament (P = 0.07) indicated calm Angus had the greatest intrinsic ECII (P ≤ 0.03) while intrinsic ECII was similar between temperamental Angus and calm and temperamental Brahman. Integrative PCI+II and ECII, and the contribution of PCI and PCI+II to overall E tended to be greater in temperamental than calm steers (P ≤ 0.09), while intrinsic ECII tended to be greater in calm than temperamental steers (P = 0.07). The impact of these mitochondrial differences on meat quality measures remains to be determined.

507 Late-Breaking: Heat Stress and Mitoq Supplementation Impact Skeletal Muscle Mitochondrial Capacities in Pigs

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 204-205
Author(s):  
Lauren T Wesolowski ◽  
Chloey P Guy ◽  
Edith J Mayorga ◽  
Tori E Rudolph ◽  
Alyssa D Freestone ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Heat Stress ◽  
Mitochondrial Function ◽  
Fixed Effects ◽  
Linear Models ◽  
Citrate Synthase ◽  
Volume Density ◽  
Semitendinosus Muscle ◽  
Mitochondrial Volume ◽  
Mitochondrial Volume Density

Abstract Heat stress can negatively impact pig health and performance but the effects of heat stress on skeletal muscle mitochondrial function are largely unknown. We hypothesized that mitochondrial function and capacity would be impaired in heat stressed (HS) compared to thermoneutral (TN) pigs but mitochondrially-targeted coenzyme Q (MitoQ) supplementation would rescue the impairment. Oxidative portions of the semitendinosus muscle were evaluated from TN and HS gilts receiving no supplementation (CON) or MitoQ for 2 d prior to and during the 24h environmental heat treatment (n = 8 per group). Mitochondrial oxidative phosphorylation (P) and electron transfer (E) capacities were determined via high resolution respirometry and mitochondrial volume density and function were quantified by citrate synthase (CS) and cytochrome c oxidase activities, respectively. Data were analyzed using linear models in SAS v9.4 with fixed effects of heat, MitoQ treatment (trt), and heat×trt interaction. There were trends for the interaction of trt and heat (P≤0.1) on integrative (per mg tissue) and intrinsic (relative to CS) P with complexes I and II (PCI+II), maximum noncoupled E (ECI+II), and E with complex II only (ECII), in which all measures were greater in HS-MitoQ than TN-MitoQ (P≤0.03), but measures did not differ due to HS in CON pigs. The contribution of leak to total E (flux control ratio, FCRLeak) was lesser in HS-MitoQ than HS-CON, TN-CON, and TN-MitoQ (P≤0.02). The FCRPCI was greater (P≤0.05) while the FCRPCI+II was lesser (P=0.01) in TN compared to HS pigs. Finally, the FCRPCI+II was greater (P=0.02) while the FCRECII tended to be lesser (P=0.09) for CON than MitoQ pigs. Neither mitochondrial volume density nor function were affected by HS or MitoQ supplementation. In total, these data indicate improved mitochondrial capacities following heat stress in pigs receiving MitoQ but no difference in mitochondrial capacities in unsupplemented, HS pigs.

scholarly journals Sexual dimorphism of substrate utilization: Differences in skeletal muscle mitochondrial volume density and function

2018 ◽  
Vol 103 (6) ◽  
pp. 851-859 ◽  
Author(s):  
David Montero ◽  
Klavs Madsen ◽  
Anne-Kristine Meinild-Lundby ◽  
Fredrik Edin ◽  
Carsten Lundby
Keyword(s):  
Skeletal Muscle ◽  
Sexual Dimorphism ◽  
Volume Density ◽  
Substrate Utilization ◽  
Mitochondrial Volume ◽  
Mitochondrial Volume Density ◽  
And Function

scholarly journals Mitochondrial Fragmentation and Dysfunction in Type IIx/IIb Diaphragm Muscle Fibers in 24-Month Old Fischer 344 Rats

2021 ◽  
Vol 12 ◽  
Author(s):  
Alyssa D. Brown ◽  
Leah A. Davis ◽  
Matthew J. Fogarty ◽  
Gary C. Sieck
Keyword(s):  
Muscle Fibers ◽  
Volume Density ◽  
Diaphragm Muscle ◽  
Type I ◽  
Mitochondrial Fragmentation ◽  
Fiber Volume ◽  
Respiratory Capacity ◽  
Dehydrogenase Reaction ◽  
Mitochondrial Volume ◽  
Mitochondrial Volume Density

Sarcopenia is characterized by muscle fiber atrophy and weakness, which may be associated with mitochondrial fragmentation and dysfunction. Mitochondrial remodeling and biogenesis in muscle fibers occurs in response to exercise and increased muscle activity. However, the adaptability mitochondria may decrease with age. The diaphragm muscle (DIAm) sustains breathing, via recruitment of fatigue-resistant type I and IIa fibers. More fatigable, type IIx/IIb DIAm fibers are infrequently recruited during airway protective and expulsive behaviors. DIAm sarcopenia is restricted to the atrophy of type IIx/IIb fibers, which impairs higher force airway protective and expulsive behaviors. The aerobic capacity to generate ATP within muscle fibers depends on the volume and intrinsic respiratory capacity of mitochondria. In the present study, mitochondria in type-identified DIAm fibers were labeled using MitoTracker Green and imaged in 3-D using confocal microscopy. Mitochondrial volume density was higher in type I and IIa DIAm fibers compared with type IIx/IIb fibers. Mitochondrial volume density did not change with age in type I and IIa fibers but was reduced in type IIx/IIb fibers in 24-month rats. Furthermore, mitochondria were more fragmented in type IIx/IIb compared with type I and IIa fibers, and worsened in 24-month rats. The maximum respiratory capacity of mitochondria in DIAm fibers was determined using a quantitative histochemical technique to measure the maximum velocity of the succinate dehydrogenase reaction (SDHmax). SDHmax per fiber volume was higher in type I and IIa DIAm fibers and did not change with age. In contrast, SDHmax per fiber volume decreased with age in type IIx/IIb DIAm fibers. There were two distinct clusters for SDHmax per fiber volume and mitochondrial volume density, one comprising type I and IIa fibers and the second comprising type IIx/IIb fibers. The separation of these clusters increased with aging. There was also a clear relation between SDHmax per mitochondrial volume and the extent of mitochondrial fragmentation. The results show that DIAm sarcopenia is restricted to type IIx/IIb DIAm fibers and related to reduced mitochondrial volume, mitochondrial fragmentation and reduced SDHmax per fiber volume.

Fiber capillarization relative to mitochondrial volume in diaphragm of shrew

2002 ◽  
Vol 93 (1) ◽  
pp. 346-353 ◽  
Author(s):  
O. Mathieu-Costello ◽  
S. Morales ◽  
J. Savolainen ◽  
M. Vornanen
Keyword(s):  
Body Mass ◽  
Fiber Surface ◽  
Volume Density ◽  
Capillary Length ◽  
Fiber Volume ◽  
Hindlimb Muscle ◽  
Mitochondrial Volume ◽  
Flight Muscles ◽  
Mitochondrial Volume Density ◽  
Sorex Minutus

The objective was to examine fiber capillarization in relation to fiber mitochondrial volume in the highly aerobic diaphragm of the shrew, the smallest mammal. The diaphragms of four common shrews [ Sorex araneus; body mass, 8.2 ± 1.3 (SE) g] and four lesser shrews ( Sorex minutus, 2.6 ± 0.1 g) were perfusion fixed in situ, processed for electron microscopy, and analyzed by morphometry. Capillary length per fiber volume was extremely high, at values of 8,008 ± 1,054 and 12,332 ± 625 mm−2 in S. araneus and S. minutus, respectively ( P= 0.012), with no difference in capillary geometry between the two species. Fiber mitochondrial volume density was 28.5 ± 2.3% ( S. araneus) and 36.5 ± 1.4% ( S. minutus; P = 0.025), yielding capillary length per milliliter mitochondria values ( S. araneus, 27.8 ± 1.5 km; S. minutus, 33.9 ± 2.2 km; P = 0.06) as high as in the flight muscle of the hummingbird and small bats. The size of the capillary-fiber interface (i.e., capillary surface per fiber surface ratio) per fiber mitochondrial volume in shrew diaphragm was also as high as in bird and bat flight muscles, and it was about two times greater than in rat hindlimb muscle. Thus, whereas fiber capillary and mitochondrial volume densities decreased with increased body mass in S. araneus compared with S. minutusSoricinae shrews, fiber capillarization per milliliter mitochondria in both species was much higher than previously reported for shrew diaphragm, and it matched that of the intensely aerobic flight muscles of birds and mammals.

Exercise training increases skeletal muscle mitochondrial volume density by enlargement of existing mitochondria and not de novo biogenesis

2017 ◽  
Vol 222 (1) ◽  
pp. e12905 ◽  
Author(s):  
A.-K. Meinild Lundby ◽  
R. A. Jacobs ◽  
S. Gehrig ◽  
J. de Leur ◽  
M. Hauser ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Exercise Training ◽  
De Novo ◽  
Volume Density ◽  
Mitochondrial Volume ◽  
Mitochondrial Volume Density

The molecular basis of aerobic metabolic remodeling differs between oxidative muscle and liver of threespine sticklebacks in response to cold acclimation

2010 ◽  
Vol 299 (1) ◽  
pp. R352-R364 ◽  
Author(s):  
J. I. Orczewska ◽  
G. Hartleben ◽  
K. M. O'Brien
Keyword(s):  
Cold Acclimation ◽  
Molecular Basis ◽  
Volume Density ◽  
Mrna Levels ◽  
Metabolic Capacity ◽  
Metabolic Genes ◽  
Acclimation Period ◽  
Metabolic Remodeling ◽  
Mitochondrial Volume ◽  
Mitochondrial Volume Density

We sought to determine the molecular basis of elevations in aerobic metabolic capacity in the oxidative muscle and liver of Gasterosteus aculeatus in response to cold acclimation. Fishes were cold- or warm-acclimated for 9 wk and harvested on days 1, 2, and 3 and weeks 1, 4, and 9 of cold acclimation at 8°C, and on day 1 and week 9 of warm acclimation at 20°C. Mitochondrial volume density was quantified using transmission electron microscopy and stereological techniques in warm- and cold-acclimated fishes harvested after 9 wk at 20 or 8°C. Changes in aerobic metabolic capacity were assessed by measuring the maximal activity of citrate synthase (CS) and cytochrome- c oxidase (COX) in fishes harvested throughout the acclimation period. Transcript levels of the aerobic metabolic genes CS, COXIII, and COXIV, and known regulators of mitochondrial biogenesis, including peroxisome proliferator-activated receptor-γ coactivators-1α and -1β (PGC-1α and PGC-1β), nuclear respiratory factor-1 (NRF-1), and mitochondrial transcription factor-A were measured in fishes harvested throughout the acclimation period using quantitative real-time PCR. The maximal activities of CS and COX increased in response to cold acclimation in both tissues, but mitochondrial volume density only increased in oxidative muscle ( P < 0.05). The time course for changes in aerobic metabolic capacity differed between liver and muscle. The expression of CS increased within 1 wk of cold acclimation in liver and was correlated with an increase in mRNA levels of NRF-1 and PGC-1β. Transcript levels of aerobic metabolic genes increased later in oxidative muscle, between weeks 4 and 9 of cold acclimation and were correlated with an increase in mRNA levels of NRF-1 and PGC-1α. These results show that aerobic metabolic remodeling differs between liver and muscle in response to cold acclimation and may be triggered by different stimuli.

Biochemical and Morphometric Properties of Mitochondrial Populations in Human Muscle Fibres

1985 ◽  
Vol 69 (2) ◽  
pp. 153-163 ◽  
Author(s):  
Anna Elander ◽  
Michael Sjöström ◽  
Fredrik Lundgren ◽  
Tore Scherstén ◽  
Ann-Christin Bylund-Fellenius
Keyword(s):  
Citrate Synthase ◽  
Mitochondrial Protein ◽  
Respiratory Control ◽  
Volume Density ◽  
Oxidative Enzyme ◽  
Muscle Fibres ◽  
Mitochondrial Fractions ◽  
Mitochondrial Volume Density ◽  
Subsarcolemmal Mitochondria ◽  
Peripheral Arterial

1. Two mitochondrial subpopulations were evaluated with biochemical and morphological techniques in human gastrocnemius muscle of 10 patients with peripheral arterial insufficiency and 12 control individuals. 2. The subsarcolemmal mitochondria were released by gentle homogenization, with a recovery of 32-37%, and the intermyofibrillar by enzymic digestion and further mechanical disintegration, recovery 18-21%. The subsarcolemmal mitochondria were morphologically defined as those located within 2 μm from the sarcolemma membrane and the intermyofibrillar mitochondria as those located in the rest of the fibre. 3. In the controls the intermyofibrillar mitochondria had a lower respiratory ratio than the subsarcolemmal, owing to a higher state II respiration. The subsarcolemmal space, which contained 25% of the mitochondria, had a mitochondrial volume density two- to three-fold that of the intermyofibrillar space in the controls. 4. The patients, who had a 48-64% higher oxidative enzyme capacity in their muscle tissue, had higher respiratory rate and respiratory control index with similar ADP/O ratio in the subsarcolemmal fraction in comparison with the controls. The citrate synthase activity was higher in both mitochondrial fractions of the patients. The volume densities of mitochondria, total as well as for both subpopulations, were also higher in the patients, which was further reflected in higher yields of mitochondrial protein. 5. The results demonstrate that both sub-populations of muscle mitochondria are able to adapt quantitatively and/or qualitatively. Furthermore, they show that the increased oxidative enzyme capacity of the patients is associated with an increased quantity of both mitochondrial populations and a qualitative improvement of the respiratory activity of the subsarcolemmal mitochondria.

Mitochondrial metabolism of cardiac and skeletal muscles from a fast (Katsuwonus pelamis) and a slow (Cyprinus carpio) fish

1992 ◽  
Vol 70 (6) ◽  
pp. 1246-1253 ◽  
Author(s):  
Christopher D. Moyes ◽  
Odile A. Mathieu-Costello ◽  
Richard W. Brill ◽  
Peter W. Hochachka
Keyword(s):  
Specific Activity ◽  
Mitochondrial Protein ◽  
Volume Density ◽  
Tissue Mass ◽  
Oxidation Rates ◽  
Muscle Tissues ◽  
Red Muscle ◽  
Rate Of Oxygen Consumption ◽  
Mitochondrial Volume ◽  
Mitochondrial Volume Density

Tuna cardiac (atrium, compact and spongy ventricle) and skeletal muscle (red and white) were compared with carp tissues to determine the importance of mitochondrial differences in supporting the high aerobic capacities in tuna. Mitochondria isolated from red muscle of both species oxidized each of the physiological fuels at similar rates per milligram of mitochondrial protein, when differences in assay temperature are considered. The highest rate of oxygen consumption by ventricle mitochondria was 2 times greater in tuna than carp. The maximal oxidation rates were 3–4 times higher in ventricle than red muscle in both species. Tuna tissues had as much as 30–80% more mitochondrial protein per gram of tissue than carp. Morphometrically this was manifested as extremely densely packed mitochondrial cristae, rather than increased mitochondrial volume densities. In general, higher aerobic capacities of tuna ventricle and red muscle are primarily attributable to greater tissue mass and, to a lesser extent, differences in the nature or quantity of mitochondria per gram of tissue. Unlike ventricle and red muscle, tissues with relatively low mitochondrial contents in carp (white muscle, atrium) demonstrated several-fold higher mitochondrial contents in tuna. Enzyme analyses of tissue and isolated mitochondria suggest a greater dependence of tuna tissues on fatty acids as fuels. Activities of carnitine palmitoyl transferase (CPT) per milligram of protein were 2–2.5 times higher in tuna red muscle and ventricle mitochondria than in carp mitochondria from the same tissues. Whole tissue activity ratios of hexokinase/CPT, which indicate the relative importance of glucose and fatty acid metabolism, were 5 times higher in carp spongy ventricle and 12 times higher in carp compact ventricle. These data suggest that muscle aerobic capacity can be increased at several levels: tissue mass, mitochondrial volume density, cristae surface density, and mitochondrial specific activity. Large differences observed between carp and tuna muscles are due to cumulative effects of several of these factors.

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