scholarly journals Condylar Degradation from Decreased Occlusal Loading following Masticatory Muscle Atrophy

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Zhan Shi ◽  
Jin Lv ◽  
Liu Xiaoyu ◽  
Li Wu Zheng ◽  
Xue-wen Yang
Keyword(s):  
Subchondral Bone ◽  
Muscle Atrophy ◽  
Masticatory Muscles ◽  
Blue Staining ◽  
Control Group ◽  
Tartrate Resistant Acid Phosphatase ◽  
Sprague Dawley ◽  
Condylar Cartilage ◽  
Cross Sectional ◽  
Soft Diet

Objective. The masticatory muscles are the most important contributor to bite force, and the temporomandibular joint (TMJ) receives direct occlusal loading. The present study aimed to investigate condylar remodeling after masseter muscle atrophy in rats.Methods. Sixty 5-week-old female Sprague-Dawley rats were divided into the following 3 groups: the control group, soft diet (SD) group, and botulinum toxin (BTX) group. The cross-sectional area (CSA) of the masseter muscles was investigated as well as atrogin-1/MuRF-1 expression. Changes in the condylar head were evaluated by H-E, toluidine blue staining, and contour measurements. The biomechanical sensitive factors PTHrP Ihh, Col2a1, and ColX of condylar cartilage were detected by immunohistochemical staining and western blotting. Furthermore, micro-CT and tartrate-resistant acid phosphatase (TRAP) staining were performed to determine the osteopenia in subchondral bone.Results. The histological and protein analysis demonstrated muscle hypofunction in the SD and BTX groups. Condylar cartilage contour was diminished due to different treatments; the immunohistochemistry and protein examination showed that the expressions of PTHrP, Ihh, Col2a1, and ColX were suppressed in condylar cartilage. A steady osteoporosis in subchondral bone was found only in the BTX group.Conclusion. The current results suggested that a steady relationship between muscular dysfunction and condylar remodeling exists.

scholarly journals Atrophy patterns in isolated subscapularis lesions

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Gernot Seppel ◽  
Andreas Voss ◽  
Daniel J. H. Henderson ◽  
Simone Waldt ◽  
Bernhard Haller ◽  
...  
Keyword(s):  
Muscle Atrophy ◽  
Area Ratio ◽  
Cross Sectional Area ◽  
Control Group ◽  
Sectional Area ◽  
Cross Sectional ◽  
Subscapularis Muscle ◽  
Mri Scans ◽  
The Mean ◽  
The Cross

Abstract Background While supraspinatus atrophy can be described according to the system of Zanetti or Thomazeau there is still a lack of characterization of isolated subscapularis muscle atrophy. The aim of this study was to describe patterns of muscle atrophy following repair of isolated subscapularis (SSC) tendon. Methods Forty-nine control shoulder MRI scans, without rotator cuff pathology, atrophy or fatty infiltration, were prospectively evaluated and subscapularis diameters as well as cross sectional areas (complete and upper half) were assessed in a standardized oblique sagittal plane. Calculation of the ratio between the upper half of the cross sectional area (CSA) and the total CSA was performed. Eleven MRI scans of patients with subscapularis atrophy following isolated subscapularis tendon tears were analysed and cross sectional area ratio (upper half /total) determined. To guarantee reliable measurement of the CSA and its ratio, bony landmarks were also defined. All parameters were statistically compared for inter-rater reliability, reproducibility and capacity to quantify subscapularis atrophy. Results The mean age in the control group was 49.7 years (± 15.0). The mean cross sectional area (CSA) was 2367.0 mm2 (± 741.4) for the complete subscapularis muscle and 1048.2 mm2 (± 313.3) for the upper half, giving a mean ratio of 0.446 (± 0.046). In the subscapularis repair group the mean age was 56.7 years (± 9.3). With a mean cross sectional area of 1554.7 mm2 (± 419.9) for the complete and of 422.9 mm2 (± 173.6) for the upper half of the subscapularis muscle, giving a mean CSA ratio of 0.269 (± 0.065) which was seen to be significantly lower than that of the control group (p < 0.05). Conclusion Analysis of typical atrophy patterns of the subscapularis muscle demonstrates that the CSA ratio represents a reliable and reproducible assessment tool in quantifying subscapularis atrophy. We propose the classification of subscapularis atrophy as Stage I (mild atrophy) in case of reduction of the cross sectional area ratio < 0.4, Stage II (moderate atrophy) in case of < 0.35 and Stage III (severe atrophy) if < 0.3.

scholarly journals The Administration of 4-Hexylresorcinol Accelerates Orthodontic Tooth Movement and Increases the Expression Level of Bone Turnover Markers in Ovariectomized Rats

2020 ◽  
Vol 21 (4) ◽  
pp. 1526 ◽  
Author(s):  
Kwang-Hyo Choi ◽  
Dae-Won Kim ◽  
Suk Keun Lee ◽  
Seong-Gon Kim ◽  
Tae-Woo Kim
Keyword(s):  
Tooth Movement ◽  
Orthodontic Tooth Movement ◽  
Ovariectomized Rats ◽  
Control Group ◽  
Tartrate Resistant Acid Phosphatase ◽  
Sprague Dawley ◽  
Osteogenic Markers ◽  
Surgical Methods ◽  
Elevated Expression ◽  
Turnover Markers

Surgical methods for accelerating orthodontic tooth movement are limited by possible damage to the tooth root and patient discomfort. 4-Hexylresorcinol (4HR) has been shown to increase bone remodeling and may potentially facilitate tooth movement. This study investigated the (1) effect of 4HR administration on osteoblast-like cells and (2) effect of 4HR administration on tooth movement in ovariectomized rats. Saos-2 cells were treated with either 4HR or solvent (control). Protein expression levels were investigated 2, 8, and 24 h after treatment. Thirty ovariectomized Sprague-Dawley rats were divided into two experimental groups (A and B) and one control group. After installation of an orthodontic tooth movement device, groups A and B received subcutaneous weekly injections of 4HR (1.28 and 128 mg/kg). Micro-computerized tomography and histological analyses were performed after 2 weeks of tooth movement. The application of 4HR elevated expression of osteogenic markers in Saos-2 cells. Movement of the first molars was significantly greater in rats administered 4HR. Furthermore, the expression of bone morphogenic protein-2, receptor activator of nuclear factor kappa-B ligand, osteocalcin, and tartrate-resistant acid phosphatase were increased after 4HR administration. 4HR application demonstrated increased expression of osteogenic markers in Saos-2 cells and accelerated orthodontic tooth movement in rats.

scholarly journals Skeletal Muscle Response to Deflazacort, Dexamethasone and Methylprednisolone

Cells ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 406 ◽  
Author(s):  
Alan Fappi ◽  
Juliana de Carvalho Neves ◽  
Leandro Nunes Sanches ◽  
Pedro Victor Massaroto e Silva ◽  
Guilherme Yuiti Sikusawa ◽  
...  
Keyword(s):  
Muscle Atrophy ◽  
Saline Solution ◽  
Fiber Type ◽  
Neuromuscular Diseases ◽  
Study Groups ◽  
Control Group ◽  
Cross Sectional ◽  
Genes Expression ◽  
Male Wistar Rats ◽  
Synthetic Glucocorticoids

Glucocorticoids represent some of the most prescribed drugs that are widely used in the treatment of neuromuscular diseases, but their usage leads to side effects such as muscle atrophy. However, different synthetic glucocorticoids can lead to different muscle effects, depending upon its chemical formulation. Here, we intended to demonstrate the muscle histologic and molecular effects of administering different glucocorticoids in equivalency and different dosages. Methods: Seventy male Wistar rats distributed into seven groups received different glucocorticoids in equivalency for ten days or saline solution. The study groups were: Control group (CT) saline solution; dexamethasone (DX) 1.25 or 2.5 mg/kg/day; methylprednisolone (MP) 6.7 or 13.3mg/kg/day; and deflazacort (DC) 10 or 20 mg/kg/day. At the end of the study, the animals were euthanized, and the tibialis anterior and gastrocnemius muscles were collected for metachromatic ATPase (Cross-sectional area (CSA) measurement), Western blotting (protein expression of IGF-1 and Ras/Raf/MEK/ERK pathways) and RT-PCR (MYOSTATIN, MuRF-1, Atrogin-1, REDD-1, REDD-2, MYOD, MYOG and IRS1/2 genes expression) experiments. Results: Muscle atrophy occurred preferentially in type 2B fibers in all glucocorticoid treated groups. DC on 10 mg/kg/day was less harmful to type 2B fibers CSA than other doses and types of synthetic glucocorticoids. In type 1 fibers CSA, lower doses of DC and DX were more harmful than high doses. DX had a greater effect on the IGF-1 pathway than other glucocorticoids. MP more significantly affected P-ERK1/2 expression, muscle fiber switching (fast-to-slow), and expression of REDD1 and MyoD genes than other glucocorticoids. Compared to DX and MP, DC had less of an effect on the expression of atrogenes (MURF-1 and Atrogin-1) despite increased MYOSTATIN and decreased IRS-2 genes expression. Conclusions: Different glucocorticoids appears to cause muscle atrophy affecting secondarily different signaling mechanisms. MP is more likely to affect body/muscles mass, MEK/ERK pathway and fiber type transition, DX the IGF-1 pathway and IRS1/2 expression. DC had the smallest effect on muscle atrophic response possibly due a delayed timing on atrogenes response.

Hypertrophy of rat plantaris muscle fibers after voluntary running with increasing loads

1998 ◽  
Vol 84 (6) ◽  
pp. 2183-2189 ◽  
Author(s):  
Akihiko Ishihara ◽  
Roland R. Roy ◽  
Yoshinobu Ohira ◽  
Yasuhiko Ibata ◽  
V. Reggie Edgerton
Keyword(s):  
Wheel Running ◽  
Fiber Type ◽  
Motor Units ◽  
Control Group ◽  
Fiber Types ◽  
Total Work ◽  
Sprague Dawley ◽  
Cross Sectional ◽  
Hypertrophic Response ◽  
Voluntary Running

There have been no systematic comparisons of skeletal muscle adaptations in response to voluntary wheel running under controlled loading conditions. To accomplish this, a voluntary running wheel for rats and mice was developed in which a known load can be controlled and monitored electronically. Five-week-old male Sprague-Dawley rats (10 rats/group) were assigned randomly to either a 1) sedentary control group (Control); 2) voluntary exercised with no load (Run-No-Load) group; or 3) voluntary exercised with additional load (Run-Load) group for 8 wk. The load for the Run-Load group was progressively increased to reach ∼60% of body weight during the last week of training. The proportions of fast glycolytic (FG), fast oxidative glycolytic (FOG), or slow oxidative (SO) fibers in the plantaris were similar in all groups. The absolute and relative plantaris weights were greater in the Run-Load group compared with the Control and Run-No-Load groups. The mean fiber cross-sectional areas of FG, FOG, and SO fibers were 20, 25, and 15% greater in the Run-Load than in Control rats. In addition, these fiber types were 16, 21, and 12% larger in Run-Load than in Run-No-Load rats. The muscle weights and mean cross-sectional areas of each fiber type were highly correlated with the average running distances and total work performed in the Run-Load, but not the Run-No-Load, group. The slope of the relationship between fiber size and running distance and total work performed was significant for each fiber type but was higher for FG and FOG fibers compared with SO fibers. These data show that the load on a rat running voluntarily can determine the magnitude of a hypertrophic response and the population of motor units that are recruited to perform at a given loading condition.

scholarly journals Effect of Clodronate Administration on the Structure of the Primary Spongiosa derived from the Growth Cartilage in Growing Rats

2019 ◽  
Vol 2 (1) ◽  
pp. 27-35
Author(s):  
Helena Gil-Peña ◽  
Ángela Fernández-Iglesias ◽  
Rocío Fuente ◽  
Laura Alonso-Duran ◽  
Fernando Santos ◽  
...  
Keyword(s):  
Growth Plate ◽  
Bone Growth ◽  
Blue Staining ◽  
Growth Spurt ◽  
Alcian Blue Staining ◽  
Tartrate Resistant Acid Phosphatase ◽  
Sprague Dawley ◽  
Proliferating Cells ◽  
Longitudinal Bone Growth ◽  
Growth Plate Cartilage

The effect of the inhibition of the resorptive activity of osteoclastic cells induced by bisphosphonate treatment on the primary spongiosa derived from the calcified cartilage of the growth plate was studied. We focused our attention on the primary spongiosa because it is the initial trabecular bone network that is first formed directly from growth plate mineralized cartilaginous septa. The study was carried out in male Sprague-Dawley rats at the age of 35 days, coinciding with the prepubertal growth spurt, a stage characterized by the highest values for growth rate. Animals were classified in two groups, controls and rats treated with clodronate 60 mg/kg/day. Body weights and tibial length were measured. The rate of longitudinal bone growth was obtained by calceine labelling and the height of the growth plate cartilage was measured. Histochemical analysis included Alcian blue staining, detection of tartrate-resistant acid phosphatise (TRAP) activity, von Kossa staining for mineralization and immunolocalization of proliferating cells. Microscopic examination revealed numerous tartrate-resistant acid phosphatase (TRAP)-positive cells at the chondroosseous junction and associated with subchondral trabeculae in control rat and that clodronate treatment induced a marked reduction of these cells. Clodronate-treated rats presented thinner subchondral trabeculae that were more irregularly oriented and decreased cell proliferation in the primary spongiosa. Results obtained showed that changes induced by clodronate treatment has little effect on the activity of the growth plate cartilage, without a significant effect on longitudinal bone growth even at doses much higher than those used in clinical practice.

scholarly journals Effects of Twin Inclined Plane Device on Adaptation and Ultrastructure Variations in Condyle of Growing Rats

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Shuo Wang ◽  
Yuhong Sun ◽  
Lulu Xia ◽  
Hanyue Li ◽  
Yan Xu ◽  
...  
Keyword(s):  
Subchondral Bone ◽  
Type Ii Collagen ◽  
Ultrastructural Changes ◽  
Control Group ◽  
Tartrate Resistant Acid Phosphatase ◽  
Type Ii ◽  
Inclined Plane ◽  
Growing Rats ◽  
Osteoclastic Activity ◽  
Experimental Group

Objective. This study investigates the effects of using a twin inclined plane device (TIPD) on the remolding and ultrastructure variation of mandibular condyle in growing rats. Materials and Methods. Forty-eight male Wistar rats (six weeks old, body weight of approximately 190–210 g) were divided into experimental group (wearing appliance, n = 32) and control group (no appliance, n = 16). Samples were collected on days 3, 14, 30, and 60. The immunohistochemical analysis for vascular endothelial growth factor (VEGF) and type II collagen was carried out. Tartrate-resistant acid phosphatase (TRAP) reaction was performed to evaluate the osteoclastic activity. Three-dimensional morphometric images were reconstructed for morphometric analysis by microcomputed tomography (micro-CT). The ultrastructure of the condylar surface was observed by scanning electron microscopy (SEM). Results. The expression of VEGF significantly increased, while the expression of type II collagen decreased in the experimental group at days 30 and 60. Furthermore, the enhanced osteoclast activity was observed under the subchondral bone, which was highest at day 30, and decreased to the lowest at day 60 in the experimental group. In addition, adaptive subchondral bone remolding in the posterior part of the condyle was observed at day 60 in the experimental group, and the SEM revealed the ultrastructure variations after installation of the TIPD. However, these changes began to reverse after 30 days. Conclusion. Condylar tissue changes point to the osteoclastic activity in the posterior region of the condyle. These adaptive changes point to bone resorption in the posterior condyle. Type II collagen and VEGF contribute to the MCC remolding induced by the TIPD. The ultrastructural changes in the posterior condylar area in response to mechanical stresses are recoverable at the initial stage.

Cadmium exposure induced itai-itai-like syndrome in male rats

Open Medicine ◽  
2011 ◽  
Vol 6 (4) ◽  
pp. 425-434 ◽  
Author(s):  
Xiao Chen ◽  
Guoying Zhu ◽  
Taiyi Jin ◽  
Shuzhu Gu ◽  
Mingguang Tan ◽  
...  
Keyword(s):  
Bone Mineral ◽  
Proximal Tibia ◽  
Cadmium Exposure ◽  
Biomechanical Analysis ◽  
Male Rats ◽  
Control Group ◽  
Biomechanical Property ◽  
Tartrate Resistant Acid Phosphatase ◽  
Sprague Dawley ◽  
Mineral Density

AbstractFourteen Sprague-Dawley male rats were randomly divided into 2 groups which were given CdCl2 at the doses of 0 and 1.5 mg /kg for 12 weeks. Before sacrifice, microCT scanning were performed on the proximal tibia and urine were collected for cadmium and N-acetyl-beta-D-glucosaminidase assay, then all of rats were sacrificed and blood was collected for biomarkers measurement; bone tissues were collected for bone mass, histology and biomechanical analysis. The cadmium in blood, urine, bone and kidney of rats treated with cadmium was significantly higher than those in the control group. The bone mineral density, and bone mineral ability of rats treated with cadmium were obviously decreased by 20%–50% compared to controls. Bone microstructure index and trabecular separation of rats treated with cadmium were obviously lower (−50%) and significantly higher (+150%) than that in the control group. Bone biomechanical property decreased by 30%–60% in cadmium treated rats compared to control. Tartrate-resistant acid phosphatase 5b and alkaline phosphatase levels of rats treated with cadmium were significantly higher than those in control, but serum osteocalcin level decreased greatly by cadmium. Obvious proximal tubule damage occurred after cadmium exposure. These observations gave clear and comprehensive evidence that cadmium exposure could induce itai-itai-like syndrome in male rats.

scholarly journals THE GREEN TEA POLYPHENOL EPIGALLOCATECHIN-3-GALLATE (EGCG) ATTENUATES SKELETAL MUSCLE ATROPHY IN A RAT MODEL OF SARCOPENIA

2015 ◽  
pp. 1-7
Author(s):  
B.M. MEADOR ◽  
K.A. MIRZA ◽  
M. TIAN ◽  
M.B. SKELDING ◽  
L.A. REAVES ◽  
...  
Keyword(s):  
Muscle Mass ◽  
Green Tea ◽  
Muscle Atrophy ◽  
Rat Model ◽  
Control Diet ◽  
Skeletal Muscle Atrophy ◽  
Sprague Dawley ◽  
Cross Sectional ◽  
Green Tea Polyphenol ◽  
Lower Protein

Objective: Sarcopenia—the loss of muscle mass and functionality occurring with age—is a pervasive problem with few effective treatments beyond exercise. We examined the ability of the green tea catechin, epigallocatechin-3-gallate (EGCg), to impact muscle mass and the molecular pathway involved in muscle atrophy in a rat model of sarcopenia. Methods: 20-month-old Sprague-Dawley rats were treated for 8 weeks with control diet or control plus 200mg/kg body weight of EGCg diet. Results: EGCg-supplemented animals had significantly greater gastrocnemius muscle mass than the aged controls, and showed a trend for increased muscle fiber cross-sectional areas (CSA) (p=0.06). These changes were associated with significantly lower protein expressions of the intramuscular 19S and 20S proteasome subunits and the MuRF1 and MAFbx ubiquitin ligases in the EGCg-treated animals. Proteasome activity as determined by ‘Chymotrypsin-like’ enzyme activity was also significantly reduced by EGCg. Muscle mRNA expression of IL-15 and IGF-1 were significantly increased in the EGCg group vs. the aged controls. In comparison to younger adult animals (6 month), the protein expression of 19S, 20S, MuRF1, MAFbx, and myostatin were increased between approximately 4- and 12-fold in the aged controls, but only up to ~2-fold in the aged EGCg animals. Conclusions: EGCg supplementation was able to preserve muscle in sarcopenic rats, partly through attenuating protein degradation via the ubiquitin-proteasome pathway, together with increased expression of anabolic factors.

scholarly journals Electrical stimulation attenuates morphological alterations and prevents atrophy of the denervated cranial tibial muscle

2017 ◽  
Vol 15 (1) ◽  
pp. 71-76 ◽  
Author(s):  
Cleuber Rodrigo de Souza Bueno ◽  
Mizael Pereira ◽  
Idvaldo Aparecido Favaretto Junior ◽  
Carlos Henrique Fachin Bortoluci ◽  
Thais Caroline Pereira dos Santos ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Muscle Atrophy ◽  
Treated Group ◽  
Control Group ◽  
Cross Sectional ◽  
Significance Level ◽  
Morphological Alterations ◽  
Morphometric Analyses ◽  
Significant Difference ◽  
Initial Control

ABSTRACT Objective To investigate if electrical stimulation through Russian current is able to maintain morphology of the cranial tibial muscle of experimentally denervated rats. Methods Thirty-six Wistar rats were divided into four groups: the Initial Control Group, Final Control Group, Experimental Denervated and Treated Group, Experimental Denervated Group. The electrostimulation was performed with a protocol of Russian current applied three times per week, for 45 days. At the end, the animals were euthanized and histological and morphometric analyses were performed. Data were submitted to statistical analysis with a significance level of p<0.05. Results The Experimental Denervated Group and the Experimental Denervated and Treated Group had cross-sectional area of smaller fiber compared to the Final Control Group. However, there was significant difference between the Experimental Denervated Group and Experimental Denervated and Treated Group, showing that electrical stimulation minimized muscle atrophy. The Experimental Denervated and Treated Group and Initial Control Group showed similar results. Conclusion Electrical stimulation through Russian current acted favorably in maintaining morphology of the cranial tibial muscle that was experimentally denervated, minimizing muscle atrophy.

scholarly journals The effect of acute dietary restriction on muscle fibre number in weanling rats

1981 ◽  
Vol 45 (3) ◽  
pp. 475-481 ◽  
Author(s):  
Donald K. Layman ◽  
Patricia B. Swan ◽  
P. V. J. Hegarty
Keyword(s):  
Dietary Restriction ◽  
Fibre Diameter ◽  
Growth Potential ◽  
Control Group ◽  
Muscle Fibres ◽  
Sprague Dawley ◽  
Muscle Weight ◽  
Cross Sectional ◽  
Restricted Group ◽  
Fibre Number

1. Male Sprague-Dawley rats were allocated at 100 g into either an ad lib.-fed control group or a food-restricted group. The restricted group was fed for 9 d at 25% of ad lib. intake. Controls were killed at a body-weight of 100 g and 29 d of age and the restricted animlas were killed at 70 g and 38 d of age.2. The effects of food restriction on muscle weight, fibre number, fibre diameter, DNA, and protein were examined in three skeletal muscles, the soleus, plantaris and extensor digitorum longus (EDL).3. Acute dietary restriction caused body- and muscle-weight loss and a decrease in both the number and cross-sectional area of muscle fibres in each of the muscles.4. The restriction halted growth-related increases in DNA in all muscles and decreased the protein: DNA value in the plantaris and EDL.5. These results indicate that present theories describing cellular development are not adequate to define growth potential or growth retardation of skeletal muscle.

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