Effects of tetrodotoxin-induced disuse on properties of developing rat gastrocnemius muscle

1984 ◽  
Vol 62 (9) ◽  
pp. 1106-1111 ◽  
Author(s):  
M. A. Lapointe ◽  
P. F. Gardiner
Keyword(s):  
Contractile Function ◽  
Muscle Growth ◽  
Nerve Impulse ◽  
Normal Growth ◽  
Fold Increase ◽  
Normal Activity ◽  
Cross Sectional ◽  
Tension Development ◽  
Short Period ◽  
Gastrocnemius Muscles

Our goal was to determine the influence of a complete lack of neuromuscular activity, during a period of rapid muscle growth, on muscle morphology and contractile function. Rats, 21 days old, had one hindlimb paralyzed for a period of 7–9 consecutive days by repetitive implantation of a silastic cuff containing tetrodotoxin (TTX), a specific nerve impulse conduction blocker, around the sciatic nerve. In situ isometric contractile properties of gastrocnemius were measured at 31 days of age, and muscles were subsequently examined histologically. Normal growth during this period resulted in a two- to three-fold increase in muscle weights, mean muscle fiber cross-sectional areas and increases in absolute twitch and tetanic tensions. After inactivity from 21 to 30 days of age, gastrocnemius muscles were smaller, and tetanically weaker, than age-matched controls. The normal cross-sectional area increase of fast-twitch fibers was preferentially affected. Inactive muscles also demonstrated significantly slower twitch responses, had higher twitch: tetanus ratios and relative tensions at 25 Hz than age-matched controls, suggesting a "slower" contractile response. On the other hand, maximum rate of tetanic tension development was elevated. These effects of inactivity appeared to be reversed by resumption of normal activity for 4 days. Neuromuscular inactivity during a relatively short period of rapid muscle growth causes significant muscle morphological and contractile changes, which are most likely reversible.

Muscle growth, cell number, type and morphometry in single and twin fetal lambs during mid to late gestation

2000 ◽  
Vol 12 (6) ◽  
pp. 319 ◽  
Author(s):  
S. A. McCoard ◽  
W. C. McNabb ◽  
S. W. Peterson ◽  
S. N. McCutcheon ◽  
P. M. Harris
Keyword(s):  
Muscle Mass ◽  
Litter Size ◽  
Muscle Growth ◽  
Cell Number ◽  
Late Gestation ◽  
Postnatal Life ◽  
Cross Sectional ◽  
Hindlimb Muscles ◽  
Full Complement ◽  
Gastrocnemius Muscles

Muscle growth, myofibre number, type and morphometry were studied in large hindlimb muscles of single and twin fetal lambs during mid to late gestation. Placental insufficiency, evident by lower total placentome weight and number per fetus, resulted in reduced fetal weights from 100 to 140 days gestation in twins compared with singletons (at 140 days: 5016 108 g v. 5750 246 g, respectively; P<0.05). However, competition between littermates did not consistently reduce muscle mass (15–22%) until 140 days gestation. Apparent myofibre number increased with age, indicating that the full complement of myofibres in some large hindlimb muscles may be achieved during early postnatal life. Litter size did not impact on apparent myofibre number in the semitendinosus, plantaris or gastrocnemius muscles. However, a transient effect on myofibre number in the adductor femoris muscle was observed from 80–120 days gestation. The phenotypic maturation of myofibres was unaffected by increasing litter size. Smaller muscle mass in twins was associated with smaller myofibre cross-sectional area in the semitendinosus, adductor femoris and gastrocnemius muscles at 140 days gestation. A similar trend was observed for the plantaris muscle. These results indicate that while competition between littermates for nutrients in late gestation can impact on both fetal and muscle mass, the fetus has the capacity to buffer against the effects of restricted nutrient supply on myofibre hyperplasia and phenotypic maturation, but myofibre hypertrophy is compromised.

The Worrying Trend of Diabetes Mellitus in Saudi Arabia: An Urgent Call to Action

2020 ◽  
Vol 16 (3) ◽  
pp. 204-210 ◽  
Author(s):  
Asirvatham A. Robert ◽  
Mohamed A. Al Dawish
Keyword(s):  
Diabetes Mellitus ◽  
Saudi Arabia ◽  
Present Report ◽  
Adult Population ◽  
Current Trend ◽  
Fold Increase ◽  
Developed Countries ◽  
Evidence Base ◽  
Small Sample ◽  
Cross Sectional

From last few years, the pervasiveness of diabetes mellitus (DM), in Saudi Arabia, is growing at a frightening rate. Overall, one-fourth of the adult population is affected by DM, which is further predicted to rise to more than double by the year 2030. The most alarming is possibly the escalation propensity of diabetes, in recent years, where a nearly ten-fold increase has been witnessed over the past thirty years in Saudi Arabia. However, the number of research arbitrations on the prevalence and incidence of DM is woefully inadequate, as compared to developed countries. Apart from this, most of the existing research data carried out in Saudi Arabia is cross-sectional, with small sample sizes, which most often involve only certain parts of the country. Consequently, the present scenario demands more multidimensional and multisectoral research to strengthen the evidence base and to accumulate greater knowledge as a basis for measures and programmes to confront diabetes and its complications. Thus, the present report makes an attempt to depict the current trend of diabetes as well as intends to put forward essential measures for controlling diabetes in Saudi Arabia.

Effect of an interval rehabilitation program with home-based, vibration-assisted training on the development of muscle and bone in children with cerebral palsy – an observational study

2020 ◽  
Vol 33 (8) ◽  
pp. 1083-1092 ◽  
Author(s):  
Ibrahim Duran ◽  
Kyriakos Martakis ◽  
Christina Stark ◽  
Leonie Schafmeyer ◽  
Mirko Rehberg ◽  
...  
Keyword(s):  
Cerebral Palsy ◽  
Bone Growth ◽  
Muscle Growth ◽  
Rehabilitation Program ◽  
Whole Body ◽  
Cross Sectional ◽  
Home Based ◽  
Children With Cerebral Palsy ◽  
One Year ◽  
Intensive Rehabilitation

AbstractObjectivesIn children with cerebral palsy (CP), the most common cause of physical impairment in childhood, less muscle and bone growth has been reported, when compared with typically developing children. The aim of this study was to evaluate the effect of an intensive rehabilitation program including physiotherapy in combination with 6 months of home-based, vibration-assisted training on muscle and bone growth in children with CP.MethodsWe included children with CP, who participated in a rehabilitation program utilizing whole-body vibration (WBV). Muscle mass was quantified by appendicular lean mass index (App-LMI) and bone mass by total-body-less-head bone mineral content (TBLH-BMC) assessed by Dual-energy X-ray absorptiometry (DXA) at the beginning of rehabilitation and one year later. To assess the functional muscle-bone unit, the relation of TBLH-BMC to TBLH lean body mass (TBLH-LBM) was used.ResultsThe study population included 128 children (52 females, mean age 11.9 ± 2.7). App-LMI assessed in kg/m2 increased significantly after rehabilitation. The age-adjusted Z-score for App-LMI showed no significant change. TBLH-BMC assessed in gram increased significantly. The Z-scores for TBLH-BMC decreased lesser than expected by the evaluation of the cross-sectional data at the beginning of rehabilitation. The parameter $\frac{TBLH-BMC}{TBLH-LBM}$ did not change relevantly after 12 months.ConclusionsMuscle growth and to a lesser extent bone growth could be increased in children with CP. The intensive rehabilitation program including WBV seemed to have no direct effect on the bone, but the observed anabolic effect on the bone, may only been mediated through the muscle.

scholarly journals Circulating levels of IGF1 are associated with muscle strength in middle-aged- and oldest-old women

2011 ◽  
Vol 164 (2) ◽  
pp. 189-196 ◽  
Author(s):  
Diana G Taekema ◽  
Carolina H Y Ling ◽  
Gerard Jan Blauw ◽  
Carel G Meskers ◽  
Rudi G J Westendorp ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Physical Performance ◽  
Handgrip Strength ◽  
Oldest Old ◽  
Muscle Growth ◽  
Serum Levels ◽  
Middle Aged ◽  
Cross Sectional ◽  
The Relationship ◽  
Circulating Levels

ObjectiveIn aging populations, poor handgrip strength has been associated with physical disability and mortality. IGF1 is an important mediator of muscle growth and regeneration affecting muscle function. We studied the relationship between circulating levels of IGF1, its binding protein 3 (IGFBP3), and handgrip strength and physical performance in middle-aged- and oldest-old subjects.DesignCross-sectional analysis in two different cohorts composed of middle-aged- (n=672, mean 63.9±6.7 years) and oldest-old subjects (n=272, all 89 years).MethodsHandgrip strength, functional performance and ability, and serum levels of IGF1 and IGFBP3 were measured in all subjects and analyzed by linear regression for men and women separately.ResultsIGF1 and IGFBP3 levels declined with chronological age and were positively associated with handgrip strength in middle-aged- and oldest-old women (both, P<0.05), but not in men of either age group. Furthermore, higher serum levels of IGF1 were associated with slower walking speed in oldest-old men (P=0.012), and serum levels of IGFBP3 were positively associated with activities of daily living in the oldest-old women (P=0.002).ConclusionThe significant relationship between IGF1 levels and muscle strength found in women but not in men suggests a gender-specific influence of IGF1 on muscle strength. Further studies are necessary to test the relationship with physical performance.

A semi-automated measurement of muscle fiber size using the Imaris software

2021 ◽  
Author(s):  
Jennifer E. Gilda ◽  
Joon-Hyuk Ko ◽  
Aviv-Yvonne Elfassy ◽  
Nadav Tropp ◽  
Anna Parnis ◽  
...  
Keyword(s):  
Muscle Atrophy ◽  
Muscle Fiber ◽  
Cross Sections ◽  
Statistical Tests ◽  
Muscle Fibers ◽  
Fluorescent Labeling ◽  
Cross Sectional ◽  
Short Period ◽  
Fiber Size ◽  
Specific Protease

The size and shape of skeletal muscle fibers are affected by various physiological and pathological conditions, such as muscle atrophy, hypertrophy, regeneration, and dystrophies. Hence, muscle fiber cross-sectional area (CSA) is an important determinant of muscle health and plasticity. We adapted the Imaris software to automatically segment muscle fibers based on fluorescent labeling of the plasma membrane, and measure muscle fiber CSA. Analysis of muscle cross sections by the Imaris semi-automated and manual approaches demonstrated a similar decrease in CSA of atrophying muscles from fasted mice compared with fed controls. In addition, we previously demonstrated that downregulation of the Ca2+-specific protease calpain-1 attenuates muscle atrophy. Accordingly, both the Imaris semi-automated and manual approaches showed a similar increase in CSA of fibers expressing calpain-1 shRNA compared with adjacent non-transfected fibers in the same muscle cross section. Although both approaches seem valid for measurements of muscle fiber size, the manual marking method is less preferable because it is highly time-consuming, subjective, and limits the number of cells that can be analyzed. The Imaris semi-automated approach is user-friendly, requires little training or optimization, and can be used to efficiently and accurately mark thousands of fibers in a short period of time. As a novel addition to the commonly used statistics, we also describe statistical tests that quantify the strength of an effect on fiber size, enabling detection of significant differences between skewed distributions that would otherwise not be detected using typical methods.

A Comparative Study between Conventional and Modified Leishman Stain

2021 ◽  
Vol 8 (2) ◽  
pp. 5-12
Author(s):  
Rizwana Abdul Hye ◽  
Bindiya Gisuthan ◽  
Indira Kariveettil
Keyword(s):  
Conventional Method ◽  
Peripheral Blood ◽  
Cross Sectional Study ◽  
Mean Value ◽  
Health Care Centre ◽  
Cross Sectional ◽  
Modified Method ◽  
Present Cross Sectional Study ◽  
Short Period

Introduction: Leishman stain has been used as the stain of choice for peripheral blood films since many decades .But it has a disadvantage of consuming 15 minutes for the procedure alone thereby increasing the turn around time of peripheral smear reporting. In this study modified Leishman stain was made by adding phenol to conventional Leishman to reduce the staining time to 3 minutes without interfering with the quality of stain. Aim: To study the quality of modified Leishman stain in comparison with conventional preparation on peripheral blood smears. Materials and Methods: The present cross-sectional study was carried out in Central Haematology laboratory of a tertiary health care centre in Southern India. A pilot study was done to determine the ideal ratio of phenol to Leishman powder in preparing modified stain without compromising the staining quality. After obtaining consent, the blood sample was collected in anticoagulated vials. Sample size was calculated to be 85.Two thin wedge smears were prepared from each sample and one was stained with conventional Leishman stain and other with modified Leishman stain. The staining characteristics were assessed and scored by an experienced pathologist in terms of 6 parameters- RBC pattern, nuclear pattern, neutrophil granules, eosinophil granules, platelets and background staining. The grades were 1, 2, 3 & 4 (poor, satisfied, good and excellent). Smears each with grades 2, 3 and 4 were selected for study. The results were analysed by Statistical Package for the Social Sciences (SPSS) software version 16.0. Result: The mean value for the staining quality using conventional method was 4.73 and for modified method was 5.39, and the total score possible is 6. Photomicrograph showed excellent results with modified Leishman stain. Thus from these values we can interpret that modified method gave much more acceptable results than that of conventional method. Conclusion: Unlike the conventional method which requires a total of 15 minutes, to complete the staining process, modified Leishman staining techniques takes only 3 minutes. Blood films can be stained within a short period of time thus aiding in rapid diagnosis and treatment of patients. Keywords: Leishman stain, Modified Leishman stain, Phenol.

Myocyte enlargement, differentiation, and proliferation kinetics in the fetal sheep heart

2007 ◽  
Vol 102 (3) ◽  
pp. 1130-1142 ◽  
Author(s):  
Sonnet S. Jonker ◽  
Lubo Zhang ◽  
Samantha Louey ◽  
George D. Giraud ◽  
Kent L. Thornburg ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cardiac Myocytes ◽  
Cardiac Myocyte ◽  
Terminal Differentiation ◽  
Normal Growth ◽  
Mass Gain ◽  
Perinatal Period ◽  
Cross Sectional ◽  
Fetal Sheep ◽  
Cardiac Growth

The generation of new myocytes is an essential process of in utero heart growth. Most, or all, cardiac myocytes lose their capacity for proliferation during the perinatal period through the process of terminal differentiation. An increasing number of studies focus on how experimental interventions affect cardiac myocyte growth in the fetal sheep. Nevertheless, fundamental questions about normal growth of the fetal heart remain unanswered. In this study, we determined that during the last third of gestation the hearts of fetal sheep grew primarily by four processes. 1) Myocyte proliferation contributed substantially to daily cardiac mass gain, and the number of cardiac myocytes continued to increase to term. 2) The (hitherto unrecognized) contribution to cardiac growth by the increase in myocyte size associated with the transition from mononucleation to binucleation (terminal differentiation) became considerable from ∼115 days of gestational age (dGA) until term (145dGA). Because binucleation became the more frequent outcome of myocyte cell cycle activity after ∼115dGA, the number of binucleated myocytes increased at the expense of the number of mononucleated myocytes. Both the interval between nuclear divisions and the duration of cell cycle activity in myocytes decreased substantially during this same period. Finally, cardiac growth was in part due to enlargement of 3) mononucleated and 4) binucleated myocytes, which grew in cross-sectional diameter but not length during the last third of gestation. These data on normal cardiac growth may enable a more detailed understanding of the consequences of experimental and pathological interventions in prenatal life.

Role of sarcoplasmic reticulum in loss of load-sensitive relaxation in pressure overload cardiac hypertrophy

1994 ◽  
Vol 266 (1) ◽  
pp. H68-H78 ◽  
Author(s):  
C. R. Cory ◽  
R. W. Grange ◽  
M. E. Houston
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Cardiac Hypertrophy ◽  
Atpase Activity ◽  
Pressure Overload ◽  
Fold Increase ◽  
Left Ventricular ◽  
Isometric Tension ◽  
Tension Development ◽  
Sequestration Potential

The loss of load-sensitive relaxation observed in the pressure-overloaded heart may reflect a strategy of slowed cytosolic Ca2+ uptake to yield a prolongation of the active state of the muscle and a decrease in cellular energy expenditure. A decrease in the potential of the sarcoplasmic reticulum (SR) to resequester cytosolic Ca2+ during diastole could contribute to this attenuated load sensitivity. To test this hypothesis, both in vitro mechanical function of anterior papillary muscles and the SR Ca2+ sequestration potential of female guinea pig left ventricle were compared in cardiac hypertrophy (Hyp) and sham-operated (Sham) groups. Twenty-one days of pressure overload induced by coarctation of the suprarenal, subdiaphragmatic aorta resulted in a 36% increase in left ventricular mass in the Hyp. Peak isometric tension, the rate of isometric tension development, and the maximal rates of isometric and isotonic relaxation were significantly reduced in Hyp. Load-sensitive relaxation were significantly reduced in Hyp. Load-sensitive relaxation quantified by the ratio of a rapid loading to unloading force step in isotonically contracting papillary muscle was reduced 50% in Hyp muscles. Maximum activity of SR Ca(2+)-adenosinetriphosphatase (ATPase) measured under optimal conditions (37 degrees C; saturating Ca2+) was unaltered, but at low free Ca2+ concentrations (0.65 microM), it was decreased by 43% of the Sham response. Bivariate regression analysis revealed a significant (r = 0.84; P = 0.009) relationship between the decrease in SR Ca(2+)-ATPase activity and the loss of load-sensitive relaxation after aortic coarctation. Stimulation of the SR Ca(2+)-ATPase by the catalytic subunit of adenosine 3',5'-cyclic monophosphate-dependent protein kinase resulted in a 2.6-fold increase for Sham but only a 1.6-fold increase for Hyp. Semiquantitative Western blot radioimmunoassays revealed that the changes in SR Ca(2+)-ATPase activity were not due to decreases in the content of the Ca(2+)-ATPase protein or phospholamban. Our data directly implicate a role for decreased SR function in attenuated load sensitivity. A purposeful downregulation of SR Ca2+ uptake likely results from a qualitative rather than a quantitative change in the ATPase and possibly one of its key regulators, phospholamban.

scholarly journals INTRAOPERATIVE NEUROMONITORING DURING SURGICAL CORRECTION OF SPRENGEL’S DEFORMITY

2020 ◽  
Vol 33 (33) ◽  
pp. 53-57
Author(s):  
Agata Maria Kaczmarek ◽  
Juliusz Huber ◽  
Przemysław Daroszewski ◽  
Maciej Zbigniew Głowacki ◽  
Agnieszka Szymankiewicz-Szukała ◽  
...  
Keyword(s):  
Motor Evoked Potentials ◽  
Perioperative Complications ◽  
Nerve Impulse ◽  
Normal Activity ◽  
Surgical Correction ◽  
Efferent Nerve ◽  
Strong Point ◽  
Sprengel’S Deformity ◽  
Increased Risk ◽  
Iatrogenic Damage

Introduction Neuromonitoring (IOM) is a procedure for verification of the nerve impulse transmission along structures of central and peripheral nervous system during surgical procedures. Motor evoked potentials (MEPs) recordings from muscles induced with electrical pulses transcranially to motor cortex centers are especially useful during the surgery with an increased risk of iatrogenic damage to efferent nerve structures. Aim of the study The aim of this report is to present the scenario of the reversible inhibition in pathways transmitting nerve impulses during surgical correction of Sprengel’s deformity with the assessment of IOM. Material and methods Nine-year old girl was admitted to the hospital due to congenital high scapula. Corrective surgery was performed using the Woodward technique with an assessment of IOM. Results The amplitudes and latencies of the MEPs from muscles of upper right extremity were recorded as decreased and increased, respectively at about 20% during the final fixation of scapula. Thanks to these recordings surgeons could prevent the permanent damage of the brachial plexus fibers, by partial releasing of applied sutures. After surgery and subsequent rehabilitation the patient returned to the normal activity in right upper extremity. Association of electromyography and MEPs results helped with ordering and controlling the course of treatment. Conclusions The benefit of IOM relay on the safety of orthopedic surgery and decreasing the number of iatrogenic perioperative complications. This diagnostic procedure is also a strong point for argumentation in hospital administration during negotiations with lawyer representing the patient when iatrogenic complication appear.

scholarly journals Positive Inotropic Effects of ATP Released via the Maxi-Anion Channel in Langendorff-Perfused Mouse Hearts Subjected to Ischemia-Reperfusion

2021 ◽  
Vol 9 ◽  
Author(s):  
Hiroshi Matsuura ◽  
Akiko Kojima ◽  
Yutaka Fukushima ◽  
Yu Xie ◽  
Xinya Mi ◽  
...  
Keyword(s):  
Contractile Function ◽  
Organic Anion ◽  
Left Ventricular ◽  
Transient Increase ◽  
Tyrode Solution ◽  
Inotropic Effects ◽  
Cl Channel ◽  
Short Period ◽  
Cl Channels ◽  
Normal Tyrode Solution

The organic anion transporter SLCO2A1 constitutes an essential core component of the ATP-conductive large-conductance anion (Maxi-Cl) channel. Our previous experiments using Langendorff-perfused mouse hearts showed that the Maxi-Cl channel contributes largely to the release of ATP into the coronary effluent observed during 10-min reperfusion following a short period (6 min) of oxygen-glucose deprivation. The present study examined the effect of endogenous ATP released via Maxi-Cl channels on the left ventricular contractile function of Langendorff-perfused mouse hearts, using a fluid-filled balloon connected to a pressure transducer. After the initial 30-min stabilization period, the heart was then perfused with oxygen-glucose-deprived Tyrode solution for 6 min, which was followed by a 10-min perfusion with oxygenated normal Tyrode solution in the absence and presence of an ATP-hydrolyzing enzyme, apyrase, and/or an adenosine A1 receptor antagonist, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX). In the absence of apyrase and DPCPX, the left ventricular developed pressure (LVDP) decreased from a baseline value of 72.3 ± 7.1 to 57.5 ± 5.5 mmHg (n = 4) at the end of 6-min perfusion with oxygen-glucose-deprived Tyrode solution, which was followed by a transient increase to 108.5 ± 16.5 mmHg during subsequent perfusion with oxygenated normal Tyrode solution. However, in the presence of apyrase and DPCPX, the LVDP decreased to the same degree during 6-min perfusion with oxygen-glucose-deprived Tyrode solution, but failed to exhibit a transient increase during a subsequent perfusion with oxygenated normal Tyrode solution. These results strongly suggest that endogenous ATP released through Maxi-Cl channels contributes to the development of transient positive inotropy observed during reperfusion after short-period hypoxia/ischemia in the heart.

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