Age-related changes and location of type I, III, IV, V and VI collagens during development of four foetal skeletal muscles of double-muscled and normal bovine animals

1999 ◽  
Vol 31 (1) ◽  
pp. 17-27 ◽  
Author(s):  
A. Listrat ◽  
B. Picard ◽  
Y. Geay
Keyword(s):  
Skeletal Muscles ◽  
Type I ◽  
Age Related ◽  
Age Related Changes

scholarly journals Age-Related Changes in Molecular and Whole Muscle Function: Role of Fat Content?

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 141-141
Author(s):  
Joseph Gordon III ◽  
Nicholas Remillard ◽  
Chad Straight ◽  
Rajakumar Nagarajan ◽  
Bruce Damon ◽  
...  
Keyword(s):  
Older Adults ◽  
Molecular Mechanisms ◽  
Fat Content ◽  
Fat Deposition ◽  
Muscle Size ◽  
Type I ◽  
Contraction Velocity ◽  
Age Related ◽  
Whole Muscle ◽  
Age Related Changes

Abstract Decreases in muscle size and function are a general consequence of old age; the precise mechanisms of these changes remain unclear. Recent studies suggest that fat deposition in muscle may also contribute to dysfunction in older adults. Fat content was quantified in the quadriceps, and its effects on function in healthy young (21-45 y) and older (65-75 y) men and women (n=44) of comparable physical activity were compared. A subset of the young matched with the older group for muscle fat content were also examined. Peak fat-free whole muscle cross-sectional area (mCSA; cm2), volume (MV; cm3), fat content (fat fraction, FF; %), specific torque (Nm/mCSA) and peak contraction velocity (Nm∙s-1) were determined using fat-water magnetic resonance imaging and dynamometry (0-300□∙s-1). To examine potential molecular mechanisms of muscle weakness, vastus lateralis biopsies were obtained (n=31) and cross-bridge kinetics of type I and II fibers were determined. FF was higher in older adults than young (8.4±1.2% (SE), 7.6±1.4; p=0.03), while mCSA (48.9±10.4 vs. 64.2±17.3), MV (1536±532 vs. 2112±708), specific torque (2.6±0.4 vs. 3.2±0.4), and peak voluntary contraction velocity (422±20 vs. 441±23) were lower in older than young (p<0.01). Type II fiber myosin attachment rate was slower and attachment time longer in older muscle (p<0.017), providing a potential mechanism for the slowing of peak contraction velocity with age. Notably, differences at the whole muscle and molecular levels remained for the subset of young and older groups matched for FF, suggesting that fat deposition in muscle does not exacerbate age-related changes in function.

Age-related changes in renal and hepatic cellular mechanisms associated with variations in rat serum thyroid hormone levels

2008 ◽  
Vol 294 (6) ◽  
pp. E1160-E1168 ◽  
Author(s):  
Elena Silvestri ◽  
Assunta Lombardi ◽  
Pieter de Lange ◽  
Luigi Schiavo ◽  
Antonia Lanni ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Total Protein ◽  
Protein Level ◽  
Monocarboxylate Transporter ◽  
Type I ◽  
Peripheral Tissues ◽  
Protein Levels ◽  
Age Related ◽  
Liver And Kidney ◽  
Age Related Changes

Aging is associated with changes in thyroid gland physiology. Age-related changes in the contribution of peripheral tissues to thyroid hormone serum levels have yet to be systematically assessed. Here, we investigated age-related alterations in the contributions of the liver and kidney to thyroid hormone homeostasis using 6-, 12-, and 24-mo-old male Wistar rats. A significant and progressive decline in plasma thyroxine occurred with age, but triiodothyronine (T3) was decreased only at 24 mo. This was associated with an unchanged protein level of the thyroid hormone transporter monocarboxylate transporter 8 (MCT8) in the kidney and with a decreased MCT8 level in the liver at 24 mo. Hepatic type I deiodinase (D1) protein level and activity declined progressively with age. Renal D1 levels were decreased at both 12 and 24 mo but D1 activity was decreased only at 24 mo. In the liver, no changes occurred in thyroid hormone receptor (TR) TRα1, whereas a progressive increase in TRβ1 occurred at both mRNA and total protein levels. In the kidney, both TRα1 and TRβ1 mRNA and total protein levels were unchanged between 6 and 12 mo but increased at 24 mo. Interestingly, nuclear TRβ1 levels were decreased in both liver and kidney at 12 and 24 mo, whereas nuclear TRα1 levels were unchanged. Collectively, our data show differential age-related changes among hepatic and renal MCT8 and D1 and TR expressions, and they suggest that renal D1 activity is maintained with age to compensate for the decrease in hepatic T3 production.

Age-Related Changes in Scleral Material Properties of the Monkey Eye

2008 ◽  
Author(s):  
Michaël J. A. Girard ◽  
Jun-Kyo F. Suh ◽  
Michael Bottlang ◽  
Claude F. Burgoyne ◽  
J. Crawford Downs
Keyword(s):  
Intraocular Pressure ◽  
Material Properties ◽  
Lamina Cribrosa ◽  
Collagen Fibers ◽  
Visual Signals ◽  
Type I ◽  
Retinal Ganglion ◽  
Age Related ◽  
The Brain ◽  
Age Related Changes

The sclera is the outer shell and principal load-bearing tissue of the eye, which consists primarily of avascular lamellae of collagen fibers. Ninety percent of the collagen fibers in the sclera are Type I, which provide the eye with necessary mechanical strength to sustain intraocular pressure (IOP). In the posterior sclera, there is a fenestrated canal, called the optic nerve head (ONH), through which the retinal ganglion cell axons pass transmitting visual signals from the retina to the brain. The opening of the ONH is structurally supported by a fenestrated connective tissue called the lamina cribrosa.

Specificity and age-related changes of antibodies to collagen type i in normal human sera

Autoimmunity ◽  
1994 ◽  
Vol 17 (3) ◽  
pp. 257-258 ◽  
Author(s):  
G. Nicoloff ◽  
D. Valcova ◽  
S. Baydanoff
Keyword(s):  
Collagen Type ◽  
Collagen Type I ◽  
Type I ◽  
Age Related ◽  
Human Sera ◽  
Normal Human ◽  
Age Related Changes

Maximal lactate steady state declines during the aging process

2003 ◽  
Vol 95 (6) ◽  
pp. 2576-2582 ◽  
Author(s):  
Craig O. Mattern ◽  
Margaret J. Gutilla ◽  
Darrin L. Bright ◽  
Timothy E. Kirby ◽  
Kenneth W. Hinchcliff ◽  
...  
Keyword(s):  
Steady State ◽  
Exercise Intensity ◽  
Citrate Synthase ◽  
Age Groups ◽  
Type I ◽  
Training Intensity ◽  
Maximal Lactate Steady State ◽  
Age Related ◽  
Competitive Cyclists ◽  
Age Related Changes

Increased participation of aged individuals in athletics warrants basic research focused on delineating age-related changes in performance variables. On the basis of potential age-related declines in aerobic enzyme activities and a shift in the expression of myosin heavy chain (MHC) isoforms, we hypothesized that maximal lactate steady-state (MLSS) exercise intensity would be altered as a function of age. Three age groups [young athletes (YA), 25.9 ± 1.0 yr, middle-age athletes (MA), 43.2 ± 1.0 yr, and older athletes (OA), 64.6 ± 2.7 yr] of male, competitive cyclists and triathletes matched for training intensity and duration were studied. Subjects performed a maximal O2 consumption (V̇o2 max) test followed by a series of 30-min exercise trials to determine MLSS. A muscle biopsy of the vastus lateralis was procured on a separate visit. There were differences ( P < 0.05) in V̇o2 max among all age groups (YA = 67.7 ± 1.2 ml · kg-1 · min-1, MA = 56.0 ± 2.6 ml · kg-1 · min-1, OA = 47.0 ± 2.6 ml · kg-1 · min-1). When expressed as a percentage of V̇o2 max, there was also an age-related decrease ( P < 0.05) in the relative MLSS exercise intensity (YA = 80.8 ± 0.9%, MA = 76.1 ± 1.4%, OA = 69.9 ± 1.5%). There were no significant age-related changes in citrate synthase activity or MHC isoform profile. The hypothesis is supported as there is an age-related decline in MLSS exercise intensity in athletes matched for training intensity and duration. Although type I MHC isoform, combined with age, is helpful in predicting ( r = 0.76, P < 0.05) relative MLSS intensity, it does not explain the age-related decline in MLSS.

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