Intermittent flow in tendon capillary bundles

1979 ◽  
Vol 46 (4) ◽  
pp. 696-702 ◽  
Author(s):  
B. A. Hills
Keyword(s):  
Skeletal Muscle ◽  
Metabolic Rate ◽  
Achilles Tendon ◽  
Guinea Pigs ◽  
Blood Perfusion ◽  
Intermittent Flow ◽  
Time Averaging ◽  
Capillary Bed ◽  
Opening And Closing

The capillary bed has been observed in the Achilles tendon of 40 bullfrogs and 10 guinea pigs for periods of up to 2 h. The opening and closing of adjacent capillaries in a perfused area follows the pattern originally described by Krogh for skeletal muscle but the frequency is slower, as anticipated from the lower metabolic rate of tendon. However, superimposed on this "flickering is a much slower process whereby whole bundles of 20–147 capillaries open and close with little overlap in the tissue areas perfused by each. Periods of no flow averaged 39 min in 70 bundles followed in bullfrogs and 43 min in 34 bundles followed in guinea pigs, although a few failed to open in 100 min. This bundle phenomenon is discussed in relation to the serious implications in mathematically modeling the exchange of gases and nutrients between blood and tissue and the possible errors in assuming time averaging when determining blood perfusion rates. Also mentioned are the likely effects of decompression on closed bundles and the notion is introduced that the bundle phenomenon may be a factor determining which tissues can be injured by decompression.

Total Capillary Bed in Striated Muscle of Guinea Pigs Native to the Peruvian Mountains

1958 ◽  
Vol 194 (3) ◽  
pp. 585-589 ◽  
Author(s):  
Enrique Valdivia
Keyword(s):  
Skeletal Muscle ◽  
Cross Sections ◽  
Guinea Pigs ◽  
Striated Muscle ◽  
Exercise Group ◽  
Adaptive Significance ◽  
Free Exercise ◽  
India Ink ◽  
Group A ◽  
Capillary Bed

The total capillary bed in skeletal muscle of guinea pigs has been determined by perfusion with India ink and counting capillaries in cross sections of gelatin embedded muscle. Comparative studies have indicated the importance of age, the muscle studied and the site where counts were performed. Capillaries were more evently distributed in the red than the white areas of the muscle. Free exercise or restriction in cages during the life span did not materially effect the results, although in cross sections some gross enlargement of the red areas was observed in the free exercise group. A significantly greater number of capillaries per square millimeter of muscle tissue were observed in the red area of muscles from animals native to the Peruvian mountains. The red area of these muscles was also more extensive than in the sea level born controls. The possible adaptive significance of these characteristics has been indicated.

Alterations in Ultrastructure of Skeletal Muscle From Newborn Guinea Pigs Following in Utero Exposure to Ethanol

1985 ◽  
Vol 43 ◽  
pp. 686-687
Author(s):  
C. Uphoff ◽  
C. Nyquist-Battie ◽  
T.B. Cole
Keyword(s):  
Skeletal Muscle ◽  
Guinea Pigs ◽  
Muscle Development ◽  
In Utero ◽  
Ethanol Exposure ◽  
Prenatally Exposed ◽  
Chronic Alcoholic ◽  
Test Kit ◽  
Food And Water Intake ◽  
Post Intubation

Ultrastructural alterations of skeletal muscle have been observed in adult chronic alcoholic patients. However, no such study has been performed on individuals prenatally exposed to ethanol. In order to determine if ethanol exposure in utero in the latter stages of muscle development was deleterious, skeletal muscle was obtained from newborn guinea pigs treated in the following manner. Six Hartly strain pregnant guinea pigs were randomly assigned to either the ethanol or the pair-intubated groups. Twice daily the 3 ethanol-treated animals were intubated with Ensure (Ross Laboratories) liquid diet containing 30% ethanol (6g/Kg pre-pregnant body weight per day) from day 35 of gestation until parturition at day 70±1 day. Serum ethanol levels were determined at 1 hour post-intubation by the Sigma alcohol test kit. For pair-intubation the Ensure diet contained sucrose substituted isocalorically for ethanol. Both food and water intake were monitored.

Respiratory Metabolism During Pregnancy in the Guinea Pig

1957 ◽  
Vol 190 (3) ◽  
pp. 425-428 ◽  
Author(s):  
Richard M. Hoar ◽  
William C. Young
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Guinea Pig ◽  
Metabolic Rate ◽  
Adrenal Cortex ◽  
Guinea Pigs ◽  
Sharp Decrease ◽  
Zona Fasciculata ◽  
Respiratory Metabolism ◽  
Morphological Differences

Oxygen consumption and heart rate during pregnancy were measured in untreated, thyroxin-injected and thyroidectomized guinea pigs given I131. From impregnation until parturition, oxygen consumption increased 7.9% in untreated females. The increase continued until 5 days postpartum when a sharp decrease occurred. The increase is not accounted for by growth of the fetal mass. Comparable increases occurred in thyroxin-injected (16.2%) and thyroidectomized (11.9%) females, although the levels throughout were higher and lower, respectively, than in intact females. Heart rate did not increase. On the contrary, statistically significant decreases occurred in the untreated and thyroxin-injected females. Although the mechanism associated with the increased metabolic rate is not known, the possibility of thyroid participation would seem to be excluded. Involvement of the adrenal cortex is suggested by morphological differences in the cells of the zona fasciculata in pregnant and nonpregnant females and by evidence cited from other studies.

Effect of short-term vitamin E deficiency on guinea pig skeletal muscle myoglobin

1959 ◽  
Vol 197 (2) ◽  
pp. 491-493 ◽  
Author(s):  
A. D. Bender ◽  
D. D. Schottelius ◽  
B. A. Schottelius
Keyword(s):  
Skeletal Muscle ◽  
Vitamin E ◽  
Guinea Pig ◽  
Guinea Pigs ◽  
Short Term ◽  
Vitamin E Deficiency ◽  
Deficient Diet ◽  
Wet Weight ◽  
Masseter Muscles ◽  
Nitrogen Percentage

Myoglobin concentration was determined in gastrocnemius and masseter muscles of guinea pigs maintained up to 15 days on vitamin E-deficient and vitamin E-supplemented diets. A statistically significant increase in myoglobin was noted in muscles of animals on the deficient diet for 15 days. That the increase was real and not apparent was attested by studies of total nitrogen, noncollagen nitrogen, percentage of solids and muscle wet weight, all of which were the same in control and experimental muscles. Histological sections and creatine excretion studies confirmed the impression of mild, incipient nutritional dystrophy.

Perivascular and tissue PO2 in contracting rat spinotrapezius muscle

1987 ◽  
Vol 252 (6) ◽  
pp. H1192-H1202 ◽  
Author(s):  
J. M. Lash ◽  
H. G. Bohlen
Keyword(s):  
Skeletal Muscle ◽  
Muscle Contractions ◽  
Large Decrease ◽  
Functional Hyperemia ◽  
Biochemical Status ◽  
Tissue Po2 ◽  
Close Proximity ◽  
Exercise Hyperemia ◽  
Capillary Bed

This study evaluated the possibility that during skeletal muscle contractions tissue O2 tension (Po2) around arterioles and venules decreases substantially more than in the middle of the capillary bed and thereby influences functional hyperemia. Periarteriolar [H+] and [K+] were also measured because most large arterioles are in close proximity to venules such that the biochemical status of the periarteriolar tissue could be influenced by a large decrease in O2 availability in the annulet of tissue surrounding the venules. Stimulation frequencies in the range of 2-12 Hz were used to activate the rat spinotrapezius muscle. Periarteriolar and capillary bed Po2, [H+], and [K+] changed during the first few minutes of stimulation but were restored to near resting concentrations as the functional hyperemia developed. However, perivenular Po2 decreased rapidly to approximately 50-60% of the resting gas tension as contractions began, and only minor recovery occurred. Elevation of tissue and periarteriolar Po2 with an O2-enriched superfusion solution did not prevent dilation during contractions to the same diameter as during the response at very low superfusion Po2. Therefore, the extent to which O2 influences arteriolar dilation and exercise hyperemia in the spinotrapezius muscle of the rat may depend less on periarteriolar and capillary bed Po2 than on the release of vasoactive materials from the nearby perivenular tissues as the availability of O2 decreases.

Increased capillarity in skeletal muscle of growing guinea pigs acclimated to cold and hypoxia

1985 ◽  
Vol 62 (2) ◽  
pp. 245-255 ◽  
Author(s):  
Natalio Banchero ◽  
Susan R. Kayar ◽  
Andrew J. Lechner
Keyword(s):  
Skeletal Muscle ◽  
Guinea Pigs

Metabolic phenotype is not associated with vulnerability to angling in bluegill sunfish (Lepomis macrochirus)

2018 ◽  
Vol 96 (11) ◽  
pp. 1264-1271 ◽  
Author(s):  
Michael J. Louison ◽  
J.A. Stein ◽  
C.D. Suski
Keyword(s):  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Recovery Time ◽  
Lepomis Macrochirus ◽  
Metabolic Phenotype ◽  
Intermittent Flow ◽  
Bluegill Sunfish ◽  
Metabolic Rates ◽  
Prior Work ◽  
Context Specific

Prior work has described a link between an individual’s metabolic rate and a willingness to take risks. One context in which high metabolic rates and risk-prone behaviors may prove to be maladaptive is in fish that strike fishing lures only to be captured by anglers. It has been shown that metabolic phenotype may be altered by angling; however, little work has assessed metabolic rate in fish and its relationship to angling vulnerability in a realistic angling trial. To address this, we subjected a set of bluegill sunfish (Lepomis macrochirus Rafinesque, 1819) to a series of angling sessions. Following this, a subset of 23 fish that had been captured at least once and 25 fish that had not been captured were assessed for metabolic phenotype (standard and maximum metabolic rates, postexercise oxygen consumption, and recovery time) via intermittent flow respirometry. Contrary to predictions, captured and uncaptured fish did not differ in any measurement of metabolic rate. These results suggest that metabolic phenotype is not a determinant of angling vulnerability within the studied context. It is possible, therefore, that previously described alterations in metabolic phenotype owing to angling pressure may be context-specific and may not apply to all species and angling contexts.

Skeletal muscle thermogenesis enables aquatic life in the smallest marine mammal

Science ◽  
2021 ◽  
Vol 373 (6551) ◽  
pp. 223-225
Author(s):  
Traver Wright ◽  
Randall W. Davis ◽  
Heidi C. Pearson ◽  
Michael Murray ◽  
Melinda Sheffield-Moore
Keyword(s):  
Skeletal Muscle ◽  
Metabolic Rate ◽  
Basal Metabolic Rate ◽  
Tissue Level ◽  
Whole Body ◽  
Sea Otter ◽  
Aquatic Life ◽  
Respiratory Capacity ◽  
Metabolic Remodeling ◽  
Whole Body Metabolism

Basal metabolic rate generally scales with body mass in mammals, and variation from predicted levels indicates adaptive metabolic remodeling. As a thermogenic adaptation for living in cool water, sea otters have a basal metabolic rate approximately three times that of the predicted rate; however, the tissue-level source of this hypermetabolism is unknown. Because skeletal muscle is a major determinant of whole-body metabolism, we characterized respiratory capacity and thermogenic leak in sea otter muscle. Compared with that of previously sampled mammals, thermogenic muscle leak capacity was elevated and could account for sea otter hypermetabolism. Muscle respiratory capacity was modestly elevated and reached adult levels in neonates. Premature metabolic development and high leak rate indicate that sea otter muscle metabolism is regulated by thermogenic demand and is the source of basal hypermetabolism.

EFFECTS OF FEEDING AND FOOD DEPRIVATION ON OXYGEN CONSUMPTION, MUSCLE PROTEIN CONCENTRATION AND ACTIVITIES OF ENERGY METABOLISM ENZYMES IN MUSCLE AND BRAIN OF SHALLOW-LIVING (SCORPAENA GUTTATA) AND DEEP-LIVING (SEBASTOLOBUS ALASCANUS) SCORPAENID FISHES

1993 ◽  
Vol 181 (1) ◽  
pp. 213-232 ◽  
Author(s):  
T. H. Yang ◽  
G. N. Somero
Keyword(s):  
Skeletal Muscle ◽  
Metabolic Rate ◽  
Food Deprivation ◽  
Enzyme Activities ◽  
Protein Concentration ◽  
White Muscle ◽  
Muscle Protein ◽  
Metabolism Enzymes ◽  
Red Muscle ◽  
Ad Libitum

The effects of feeding and fasting were examined on the deep-living short-spine thornyhead (Sebastolobus alascanus) and the confamilial shallow-living spotted scorpionfish (Scorpaena guttata) to determine whether the low metabolic rate of the deeper-living species was in part a consequence of food deprivation in its habitat. Laboratory acclimation for periods of 90–115 days under either ad libitum feeding or complete fasting did not lead to similar rates of respiration in individuals of the two species held under identical conditions. Respiration of fish fed ad libitum was 52 % (S. guttata) or 68 % (S. alascanus) higher than for fasted fish of the same species. Furthermore, the metabolic rates of freshly collected specimens of S. alascanus resembled those of laboratory-fasted fish. In white skeletal muscle, both total protein concentration and the activities of four enzymes of ATP metabolism, lactate dehydrogenase (LDH) and pyruvate kinase (PK) of glycolysis, malate dehydrogenase (MDH) and citrate synthase (CS, a citric acid cycle indicator), were lower in S. alascanus than in S. guttata. Within a species, protein concentration and activities of the four enzymes in white muscle, but not in brain, were higher in fed than in starved fish, although these differences were greater in S. alascanus than in S. guttata. During fasting, LDH and PK activity in white muscle of S. alascanus decreased much more than MDH and CS activity; decreases in enzyme activities in red muscle were smaller than those in white muscle. Activities of enzymes in white skeletal muscle of field-collected S. alascanus generally resembled those of the fasted specimens. In contrast, red muscle of field- collected S. alascanus, compared with that of either fed or starved laboratory-held specimens, had a highly glycolytic poise (high LDH and PK activities relative to MDH and CS activities), which may suggest that muscle enzyme activities in the field-collected fish reflect adaptation to the low oxygen level in its adult habitat, the oxygen minimum layer. The strong correlations found between tissue biochemical properties and respiration rate allow us to develop a predictive index for metabolic rate from simple biochemical analyses, e.g. white muscle protein content or CS activity. We conclude that the low metabolic rate of S. alascanus is due to at least four depth-related factors: reduced abundance of food, low temperature, low ambient oxygen concentration and darkness, which may select for reduced locomotory activity.

scholarly journals Decreased Mitochondrial Dynamics Is Associated with Insulin Resistance, Metabolic Rate, and Fitness in African Americans

2019 ◽  
Vol 105 (4) ◽  
pp. 1210-1220 ◽  
Author(s):  
John J Dubé ◽  
Michael L Collyer ◽  
Sara Trant ◽  
Frederico G S Toledo ◽  
Bret H Goodpaster ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Insulin Sensitivity ◽  
Metabolic Rate ◽  
African American Women ◽  
Racial Differences ◽  
Mitochondrial Dynamics ◽  
Resting Metabolic Rate ◽  
Gene Array ◽  
Mitochondrial Capacity

Abstract Context African American women (AAW) have a higher incidence of insulin resistance and are at a greater risk for the development of obesity and type 2 diabetes than Caucasian women (CW). Although several factors have been proposed to mediate these racial disparities, the mechanisms remain poorly defined. We previously demonstrated that sedentary lean AAW have lower peripheral insulin sensitivity, reduced maximal aerobic fitness (VO2max), and lower resting metabolic rate (RMR) than CW. We have also demonstrated that skeletal muscle mitochondrial respiration is lower in AAW and appears to play a role in these racial differences. Objective The goal of this study was to assess mitochondrial pathways and dynamics to examine the potential mechanisms of lower insulin sensitivity, RMR, VO2max, and mitochondrial capacity in AAW. Design To achieve this goal, we assessed several mitochondrial pathways in skeletal muscle using gene array technology and semiquantitative protein analysis. Results We report alterations in mitochondrial pathways associated with inner membrane small molecule transport genes, fusion–fission, and autophagy in lean AAW. These differences were associated with lower insulin sensitivity, RMR, and VO2max. Conclusions Together these data suggest that the metabolic racial disparity of insulin resistance, RMR, VO2max, and mitochondrial capacity may be mediated by perturbations in mitochondrial pathways associated with membrane transport, fission–fusion, and autophagy. The mechanisms contributing to these differences remain unknown.

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