Long-term isoprenaline administration produces an increase in capillarity in the soleus muscle of the rat

1987 ◽  
Vol 65 (3) ◽  
pp. 303-306 ◽  
Author(s):  
A. H. Sillau ◽  
Maria De Lourdes Philippi
Keyword(s):  
Soleus Muscle ◽  
Cross Sections ◽  
Citrate Synthase ◽  
Lactic Dehydrogenase ◽  
Capillary Density ◽  
Oxidative Capacity ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Adrenergic Stimulation ◽  
Cross Sectional

The effects of isoprenaline administration (300 μg/kg for 5 weeks) on rat soleus muscle capillarity and glycolytic and oxidative capacities were evaluated. The treatment resulted in ventricular hypertrophy. The activities of lactic dehydrogenase, pyruvate kinase, citrate synthase, and cytochrome c oxidase in soleus muscle homogenates were not different between control and isoprenaline-injected animals. Capillaries were visualized in muscle cross sections treated to demonstrate ATPase activity after acid preincubation. Capillary density was higher in the experimental (873 ± 38 capillaries/mm2) than in the control (713 ± 33 capillaries/mm2) animals. Capillary to fiber ratio was also higher in the experimental (2.47 ± 0.10) than in control (2.09 ± 0.08) animals, but fiber cross-sectional area was not changed by the treatment (2836 ± 87 μm2 in controls and 2951 ± 136 μm2 in experimental). A plot of capillary to fiber ratio vs. fiber cross-sectional area showed that at a given fiber cross-sectional area the value of capillary to fiber ratio of the treated animals was higher than that of the controls. This indicates that treatment resulted in the proliferation of microvessels. The results suggest that prolonged β-adrenergic stimulation results in the development of new capillaries but that this is not accompanied by increases in the oxidative capacity of the soleus muscle of the rat.

scholarly journals Influence of intermittent administration of parathyroid hormone on muscle tissue and bone healing in orchiectomized rats or controls

2011 ◽  
Vol 209 (1) ◽  
pp. 9-19 ◽  
Author(s):  
Marina Komrakova ◽  
Carsten Krischek ◽  
Michael Wicke ◽  
Stephan Sehmisch ◽  
Mohammad Tezval ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Parathyroid Hormone ◽  
Bone Healing ◽  
Citrate Synthase ◽  
Capillary Density ◽  
Cross Sectional Area ◽  
Male Rats ◽  
Favorable Effect ◽  
Sectional Area ◽  
Cross Sectional

Influence of human parathyroid hormone (hPTH 1–34) on muscle and bone healing was studied in either orchiectomized (Orx at 8 months of age) or sham-operated male rats. Eleven-month-old Sprague–Dawley rats underwent bilateral transverse metaphyseal osteotomy of tibia and were divided into four groups (n=12): 1) sham-vehicle, 2) sham group-PTH everyday, 3) Orx-vehicle, 4) Orx-PTH everyday, and 5) Orx-PTH every other day. PTH dosage was 40 μg/kg body weight. After 5 weeks, fiber cross-sectional area, capillary density, and enzyme activity (lactate dehydrogenase, citrate synthase, and complex I) were measured in soleus (MS), gastrocnemius (MG), and longissimus (ML) muscles; tibiae were analyzed by computed tomographical, histological, and gene expression analyses. The effect of PTH in all rats was increased serum osteocalcin, cortical and callus densities and callus area. In sham rats capillary density was increased in limb muscles (MS: 1.3–1.7, MG: 1.2–1.4 capillaries/fiber), and rate of osseous bridging of osteotomy was enhanced (67–100%). In Orx rats serum creatine kinase was decreased (6670–2847 U/l), and bone genes (Igf-1, osteoprotegerin, and receptor activator of nuclear factor kB ligand) were up-regulated. Cross-sectional area, enzyme activity, food intake, weight of body, visceral organs, adipose tissue, MG, and MS were not affected by PTH. PTH had a favorable effect on muscle capillary density and improved bone healing being more effective in sham rats and having no adverse systemic effect. The effect was less if PTH was applied every other day. The findings may show up trends for therapeutic treatment of male patients.

Comparison of the Cross Sectional Area, the Loss in Volume and the Mechanical Properties of LAE442 and MgCa0.8 as Resorbable Magnesium Alloy Implants after 12 Months Implantation Duration

2010 ◽  
Vol 638-642 ◽  
pp. 675-680 ◽  
Author(s):  
Martina Thomann ◽  
Nina von der Höh ◽  
Dirk Bormann ◽  
Dina Rittershaus ◽  
C. Krause ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cross Sections ◽  
Degradation Process ◽  
Cross Sectional Area ◽  
Bending Test ◽  
Sectional Area ◽  
Cross Sectional ◽  
Initial Strength ◽  
Three Point Bending ◽  
The Cross

Current research focuses on magnesium based alloys in the course of searching a resorbable osteosynthetic material which provides sufficient mechanical properties besides a good biocompatibility. Previous studies reported on a favorable biocompatibility of the alloys LAE442 and MgCa0.8. The present study compared the degradation process of cylindrical LAE442 and MgCa0.8 implants after 12 months implantation duration. Therefore, 10 extruded implants (2.5 x 25 mm, cross sectional area 4.9 mm²) of both alloys were implanted into the medullary cavity of both tibiae of rabbits for 12 months. After euthanization, the right bone-implant-compound was scanned in a µ-computed tomograph (µCT80, ScancoMedical) and nine uniformly distributed cross-sections of each implant were used to determine the residual implants´ cross sectional area (Software AxioVisionRelease 4.5, Zeiss). Left implants were taken out of the bone carefully. After weighing, a three-point bending test was carried out. LAE442 implants degraded obviously slower and more homogeneously than MgCa0.8. The mean residual cross sectional area of LAE442 implants was 4.7 ± 0.07 mm². MgCa0.8 showed an area of only 2.18 ± 1.03 mm². In contrast, the loss in volume of LAE442 pins was more obvious. They lost 64 % of their initial weight. The volume of MgCa0.8 reduced clearly to 54.4 % which corresponds to the cross sectional area results. Three point bending tests revealed that LAE442 showed a loss in strength of 71.2 % while MgCa0.8 lost 85.6 % of its initial strength. All results indicated that LAE442 implants degraded slowly, probably due to the formation of a very obvious degradation layer. Degradation of MgCa0.8 implants was far advanced.

scholarly journals The accuracy of land form presentation in forest road Cross sections

2002 ◽  
pp. 91-99
Author(s):  
Bogdan Stefanovic ◽  
Velimir Aleksic
Keyword(s):  
Cross Sections ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Land Form ◽  
Volume Calculation ◽  
Forest Road ◽  
Earth Material ◽  
Legal Provisions ◽  
Natural Land

Accurate presentation of natural land forms directly affects the accuracy of earth volume calculation, the component of technical documentation of the forest road master project. Consistent to legal provisions, forest road master project is characterised by high accuracy of the planned scope of works compared to the realised scope of works, which should amount to ?3%. The volume of earth material is calculated based on the road cross-sectional area and the distance between the cross sections. The accuracy of the area of cross sections depends on the accuracy of land form presentation Accurate presentation of natural land forms depends on a great number of factors, the most significant of which are the methods of surveying and acquisition of data necessary for land form presentation, preciseness of equipment and instruments used in surveying and acquisition of data, and the method of land form presentation. The accuracy of earth material volume calculation depends on the method of computation, method of presentation of natural and artificial cross sections, and the phase of design. The presentation of natural land form in the width occupied by roadway cross section depends on the validity of the obtained station point elevation (Ht) and the elevations of detailed points (Hi). A relevant factor of the accuracy of cross sectional area, compared to its other elements, is the accuracy of the depth of cut or the height of fill (h) which should agree with the required accuracy, i.e. the adopted tolerance of the earthwork bill of quantities deviation up to 3%.

Rat diaphragm during postnatal development. I. Changes in distribution of muscle fibre type and in oxidative potential

1996 ◽  
Vol 8 (3) ◽  
pp. 391 ◽  
Author(s):  
MD Fratacci ◽  
M Levame ◽  
A Rauss ◽  
H Bousbaa ◽  
G Atlan
Keyword(s):  
Muscle Fibre ◽  
Fibre Type ◽  
Oxidative Capacity ◽  
Cross Sectional Area ◽  
Fibre Types ◽  
Type I ◽  
Sectional Area ◽  
Rat Diaphragm ◽  
Oxidative Potential ◽  
Cross Sectional

The changes occurring in the histochemical characteristics of the rat diaphragm during the postnatal period were examined. Fibre-type distribution, fibre oxidative capacity, i.e. succinate-dehydrogenase (SDH) activity, and cross-sectional area were compared in the costal (COS) and crural (CRU) regions, and across their abdominal and thoracic surfaces. The proportions of type I and IIb fibres in both COS and CRU increased with age, while the proportion of type IIa fibres progressively decreased. For COS, fibre distribution was homogeneous over the entire muscle and did not change after 4 weeks. For CRU, it was heterogeneous with a higher proportion of type I fibres on the thoracic surface as from the first week. All fibre types significantly increased in cross-sectional area between 1 and 8 weeks, with no significant differences in COS and CRU. Mean SDH activity did not differ between COS and CRU or across the muscles. Mean SDH activities-were low and identical in all fibre types at birth, and then increased, peaking at the 6th week in type I and IIa fibres. When total muscle fibre oxidative capacity was calculated from an index including fibre-type proportion, cross-sectional area and mean SDH activity, it was significantly higher at 1 than at 8 weeks after birth; this might have functional implications for the newborn.

Genetic Effects on Skeletal Mechanosensitivity in Mice

2002 ◽  
Author(s):  
Charles H. Turner ◽  
Alexander G. Robling
Keyword(s):  
Mechanical Loading ◽  
Cross Sections ◽  
Inbred Mouse ◽  
Cross Sectional Area ◽  
Mouse Strains ◽  
Sectional Area ◽  
Mineral Density ◽  
Bone Apposition ◽  
Cross Sectional ◽  
Total Cross Sectional Area

The accumulation of bone mass during growth can be enhanced by environmental factors such as mechanical loading (exercise) or calcium intake, but 60–70% of the variance in adult bone mineral density (BMD) is explained by heredity. Consequently, understanding the signaling pathways targeted by the genes governing bone accumulation holds perhaps the greatest potential in reducing fracture incidence later in life. Rodent models are particularly useful for studying the genetics of skeletal traits. Of the available inbred mouse strains, three in particular have been studied extensively in skeletal genetics: C57BL/6, DBA/2, and C3H/He. The C57BL/6 strain is characterized by low BMD and large total cross-sectional area (CSA) in the midshaft femur; the C3H/He strain exhibits very high femoral BMD and a smaller femoral CSA than the C57BL/6 mice; and DBA/2 mice have moderately high femoral BMD and a very small midshaft femur CSA. Mechanical loading of the skeleton during growth can substantially enhance periosteal bone apposition, and ultimately produce a diaphyseal cross section with enlarged area. Therefore we hypothesized that the mouse strain with greater femoral cross-sectional area (C57BL/6) might have a genetic predisposition for greater mechanosensitivity than mice with smaller cross sections (C3H/He and DBA/2).

Absence of a growth hormone effect on rat soleus atrophy during a 4-day spaceflight

1993 ◽  
Vol 74 (2) ◽  
pp. 527-531 ◽  
Author(s):  
B. Jiang ◽  
R. R. Roy ◽  
C. Navarro ◽  
V. R. Edgerton
Keyword(s):  
Growth Hormone ◽  
Succinate Dehydrogenase ◽  
Cross Sections ◽  
Fiber Type ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Fast Myosin ◽  
Hormone Effect ◽  
Fast Myosin Heavy Chain

The objectives of the present study were to determine the size and enzyme properties of soleus fibers of rats subjected to a 4-day spaceflight (National Aeronautics and Space Administration, STS-41) and the effects of exogenous growth hormone (GH) on the atrophic response of the muscle. Four groups of rats were studied: 1) control (Con), 2) Con plus GH treated (Con + GH), 3) flight (Fl), and 4) F1 plus GH treated (Fl + GH). Cross-sectional area and the activities of succinate dehydrogenase and myofibrillar adenosinetriphosphatase (ATPase) were determined in fibers identified in frozen serial cross sections. Fibers were categorized immunohistochemically as slow, fast, or slow-fast on the basis of their reaction with slow and fast myosin heavy-chain (MHC) monoclonal antibodies. Fibers also were categorized as light or dark on the basis of their staining for ATPase at pH 8.6. After the 4-day flight, mean body weight was significantly decreased compared with control. The absolute and relative (muscle wt/body wt) soleus weights were significantly smaller in the Fl and Fl + GH rats compared with their respective ground-based controls. In both flight groups, the cross-sectional area of the light ATPase fibers was significantly smaller (approximately 30%) than control. Three of 11 flight rats had a higher proportion of fibers expressing both slow and fast MHCs than expected on the basis of the fiber type distribution in the 11 control rats. Mean fiber succinate dehydrogenase and ATPase activities were similar among the four groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Influences of physical conditioning and deconditioning on coronary vasculature of dogs

1978 ◽  
Vol 45 (4) ◽  
pp. 619-625 ◽  
Author(s):  
H. L. Wyatt ◽  
J. Mitchell
Keyword(s):  
Basement Membrane ◽  
Capillary Density ◽  
Cross Sectional Area ◽  
Membrane Thickness ◽  
Physical Conditioning ◽  
Sectional Area ◽  
Circumflex Artery ◽  
Cross Sectional ◽  
Coronary Vasculature ◽  
Basement Membrane Thickness

To investigate the effects of physical conditioning and deconditioning on the coronary vasculature, eight dogs were exercised by treadmill running. Five dogs were deconditioned by confinement in cages following the conditioning period. A technique was developed and validated for measuring circumflex coronary artery diameter from magnified projections of standardized coronary angiograms. Myocardial capillary density, perimeter, and basement membrane thickness were determined from electron microscopy of serial ventricular septal biopsy samples. Physical conditioning caused a small but statistically significant increase in cross-sectional area of the circumflex artery. Although physical conditioning caused no statistically significant changes in the myocardial capillaries, trends were apparent for increases in density and perimeter of myocardial capillaries and a decrease in basement membrane thickness. Physical deconditioning caused statistically significant reductions in cross-sectional area of the circumflex artery and in myocardial capillary density but little change in perimeter or basement membrane thickness of myocardial capillaries. The results suggest that physical conditioning may be associated with an improvement in coronary vascular capacity which may regress rapidly with deconditioning.

scholarly journals The assessment sectional area of stem wood and stocks in experimental trees reclamation Western Donbass plot № 1

2016 ◽  
Vol 45 ◽  
pp. 76-81
Author(s):  
V. M. Zverkovsky ◽  
O. S. Zubkova
Keyword(s):  
Cross Sections ◽  
Linear Growth ◽  
Cross Sectional Area ◽  
Forest Plantations ◽  
Sectional Area ◽  
Cross Sectional ◽  
Stem Wood ◽  
Diameter At Breast Height ◽  
Breast Height

The linear growth of forest plantations of Western Donbass’ recultivating plot №1 were studied. The established cross-sectional the area of trunks and timber reserves experimental trees.Characterized by parameters which are the volume of wood: its height, diameter at breast height and shape of the forming barrel. In diameter at breast height cross sectional area is determined and then the barrel volume is calculated. Cross sections of tree trunks are shaped like a circle or an ellipse. Knowing the volume of logs we calculated reserves of wood for trees experimental plots.The largest reserves of timber and cross-sectional area characterized planting U. pumila – 15,367 m3 and 1,9583 m2, A. platanoides – 13,328 m3 and 2,67 m2, Q. robur – 10,120 m3 and 1,452 m2, J. virginiana – 8,748 m3 and 2,106 m2. The least plantation stocks of wood characterized E. angustifolia – 1,3699 m3 and 0,3693 m2, R. pseudoacacia – 2,9478 m3 and 0,8350 m2, P. rallasiana – 3,1626 m3 and 0,3279 m2.

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