scholarly journals Age-related Cellular and Microstructural Changes in the Rotator Cuff Enthesis

2021 ◽  
Author(s):  
Zeling Long ◽  
Koichi Nakagawa ◽  
Zhanwen Wang ◽  
Peter C Amadio ◽  
Chunfeng Zhao ◽  
...  
Keyword(s):  
Rotator Cuff ◽  
Osteogenic Potential ◽  
Aged Rats ◽  
Chondrogenic Potential ◽  
Rotator Cuff Injuries ◽  
Age Related ◽  
Mineralized Zone ◽  
Frequent Site ◽  
Potential Therapeutics ◽  
Age Related Changes

Rotator cuff injuries increase with age. The enthesis is the most frequent site of rotator cuff injury and degeneration. Understanding age-related changes of the enthesis are essential to determine the mechanism of rotator cuff injuries, degeneration, and to guide mechanistically driven therapies. In this study, we explored age-related cellular changes of the rotator cuff enthesis in young, mature, and aged rats. Here we found that the aged enthesis is typified by an increased mineralized zone and decreased non-mineralized zone. Proliferation, migration, and colony forming potential of rotator cuff derived cells (RCECs) was attenuated with aging. The tenogenic and chondrogenic potential were significantly reduced, while the osteogenic potential increased in aged RCECs. The adipogenic potential increased in RCECs with age. This study explores the cellular differences found between young, mature, and aged rotator cuff enthesis cells and provides a basis for further delineation of mechanisms and potential therapeutics for rotator cuff injuries.

Age-related changes in endothelium-dependent hyperpolarization in the rat mesenteric artery

1993 ◽  
Vol 265 (2) ◽  
pp. H509-H516 ◽  
Author(s):  
K. Fujii ◽  
S. Ohmori ◽  
M. Tominaga ◽  
I. Abe ◽  
Y. Takata ◽  
...  
Keyword(s):  
Mesenteric Artery ◽  
K Channel ◽  
Aged Rats ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Wky Rats ◽  
Age Related ◽  
Rat Mesenteric Artery ◽  
Wistar Kyoto ◽  
Age Related Changes

This study was designed to determine the age-related changes in the endothelium-dependent hyperpolarization to acetylcholine (ACh) and its contribution to relaxation in the isolated mesenteric artery from normotensive and hypertensive rats. Membrane potentials and contractions were recorded in arteries from male Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR) that were 5-6 wk old (young), 6-8 mo old (adult), and 20-26 mo old (aged). Endothelium-dependent hyperpolarizations produced by ACh, applied both at the resting state of the membrane and under conditions of depolarization with norepinephrine (10(-5) M), were markedly impaired in aged WKY rats, adult SHR, and aged SHR. Endothelium-dependent relaxations to ACh in arterial rings precontracted with 10(-5) M norepinephrine were also impaired in aged WKY rats, adult SHR, and aged SHR even in the presence of indomethacin. Furthermore, in these rats, N omega-nitro-L-arginine, an inhibitor of nitric oxide formation, showed potent inhibitory effects on the relaxations, whereas the 20 mM high K+ solution that reduces hyperpolarization had less pronounced effects. Hyperpolarizations and relaxations to cromakalim (10(-5) M), a K(+)-channel opener, were on the whole preserved in aged rats. It would thus appear that the endothelium-dependent hyperpolarization to ACh is reduced with aging as well as by hypertension, and this would, in part, account for the impaired relaxation to ACh in arteries of both aged rats and hypertensive rats.

Age-related changes affect rat rotator cuff muscle function

2014 ◽  
Vol 23 (1) ◽  
pp. 91-98 ◽  
Author(s):  
Johannes F. Plate ◽  
Lauren A. Pace ◽  
Thorsten M. Seyler ◽  
Ramon J. Moreno ◽  
Thomas L. Smith ◽  
...  
Keyword(s):  
Rotator Cuff ◽  
Muscle Function ◽  
Rotator Cuff Muscle ◽  
Age Related ◽  
Age Related Changes

scholarly journals Multiscale Poroviscoelastic Compressive Properties of Mouse Supraspinatus Tendons Are Altered in Young and Aged Mice

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Brianne K. Connizzo ◽  
Alan J. Grodzinsky
Keyword(s):  
Rotator Cuff ◽  
Structural Parameters ◽  
Hydraulic Permeability ◽  
Aged Mouse ◽  
Compressive Properties ◽  
External Compression ◽  
Tendon Degeneration ◽  
Compressive Response ◽  
Age Related ◽  
Age Related Changes

Rotator cuff disorders are one of the most common causes of shoulder pain and disability in the aging population but, unfortunately, the etiology is still unknown. One factor thought to contribute to the progression of disease is the external compression of the rotator cuff tendons, which can be significantly increased by age-related changes such as muscle weakness and poor posture. The objective of this study was to investigate the baseline compressive response of tendon and determine how this response is altered during maturation and aging. We did this by characterizing the compressive mechanical, viscoelastic, and poroelastic properties of young, mature, and aged mouse supraspinatus tendons using macroscale indentation testing and nanoscale high-frequency AFM-based rheology testing. Using these multiscale techniques, we found that aged tendons were stiffer than their mature counterparts and that both young and aged tendons exhibited increased hydraulic permeability and energy dissipation. We hypothesize that regional and age-related variations in collagen morphology and organization are likely responsible for changes in the multiscale compressive response as these structural parameters may affect fluid flow. Importantly, these results suggest a role for age-related changes in the progression of tendon degeneration, and we hypothesize that decreased ability to resist compressive loading via fluid pressurization may result in damage to the extracellular matrix (ECM) and ultimately tendon degeneration. These studies provide insight into the regional multiscale compressive response of tendons and indicate that altered compressive properties in aging tendons may be a major contributor to overall tendon degeneration.

Age-related changes in the expression and oxidation of bronchoalveolar lavage proteins in the rat

2009 ◽  
Vol 296 (1) ◽  
pp. L14-L29 ◽  
Author(s):  
Todd M. Umstead ◽  
Willard M. Freeman ◽  
Vernon M. Chinchilli ◽  
David S. Phelps
Keyword(s):  
Young Adult ◽  
Bronchoalveolar Lavage ◽  
Host Defense ◽  
Time Of Flight ◽  
Aged Rats ◽  
Juvenile Rats ◽  
2D Dige ◽  
Maldi Tof ◽  
Age Related ◽  
Age Related Changes

The incidence and severity of many lung diseases change with age. Some diseases, such as pneumonia, occur with increased frequency in children and the elderly. Proteins obtained by bronchoalveolar lavage (BAL) serve as the first line of defense against inhaled toxins and pathogens. Age-related changes in BAL protein expression and oxidative modification were examined in juvenile (1 mo), young adult (2 mo), and aged (18 mo) F344 rats using two-dimensional difference gel electrophoresis (2D-DIGE), matrix-assisted laser desorption ionization-time of flight/time of flight (MALDI-ToF/ToF) tandem mass spectrometry, and carbonyl immunoblotting. Using 2D-DIGE, we detected 563 protein spots, and MALDI-ToF/ToF identified 204 spots comprising 31 proteins; 21 changed significantly (17 increases) between juvenile and young adult or aged rats, but for 12 of these proteins, levels had a biphasic pattern, and levels in aged rats were less than in young adults. Relative carbonylation was determined by comparison of immunostaining with total protein staining on each oxidized protein blot. We found that aged rats had significantly increased oxidation in 13 proteins compared with juvenile rats. Many of the proteins altered in expression or oxidation level had functions in host defense, redox regulation, and protein metabolism. We speculate that low levels of expression of host defense proteins in juvenile rats and decreases in levels of these proteins between young adult and aged rats may predispose these groups to pneumonia. In addition, we have shown age-related increases in protein oxidation that may compromise host defense function in aged rats.

Sleep changes induced by lipopolysaccharide in the rat are influenced by age

2001 ◽  
Vol 280 (2) ◽  
pp. R398-R403 ◽  
Author(s):  
Thomas Schiffelholz ◽  
Marike Lancel
Keyword(s):  
Wave Activity ◽  
Immune Challenge ◽  
Aged Rats ◽  
Rapid Eye Movement Sleep ◽  
Middle Aged ◽  
Age Related ◽  
Sleep Alterations ◽  
Electroencephalogram Eeg ◽  
Elevated Body Temperature ◽  
Age Related Changes

In mammals, aging is associated with immune senescense. To examine whether the sleep changes occurring during immune challenge are affected by age, we assessed sleep alterations induced by the administration of lipopolysaccharide (LPS) in young and middle-aged rats. During vehicle, the middle-aged rats exhibited less pre-rapid eye movement sleep (pre-REMS) as well as REMS, due to a smaller number and shorter duration of REMS episodes, than young rats. LPS elevated body temperature, increased non-REMS, and suppressed both pre-REMS and REMS in the young as well as in the middle-aged rats. However, in the young animals, LPS significantly enhanced slow-wave activity in the electroencephalogram (EEG) within non-REMS, reflecting an increase in sleep intensity. In contrast, LPS attenuated EEG power in most frequency bands in the older animals. This finding indicates age-related changes in the modulation of sleep by LPS.

Physiology of the aged Fischer 344 rat inferior colliculus: responses to contralateral monaural stimuli

1996 ◽  
Vol 76 (5) ◽  
pp. 3114-3125 ◽  
Author(s):  
P. S. Palombi ◽  
D. M. Caspary
Keyword(s):  
Inferior Colliculus ◽  
Response Pattern ◽  
Aged Rats ◽  
Temporal Response ◽  
Fischer 344 ◽  
Young Rats ◽  
Age Related ◽  
Intensity Functions ◽  
F344 Rats ◽  
Age Related Changes

1. Presbycusis, age-related hearing loss, is an ever increasing problem in our aging society. It involves changes in both the peripheral and central portions of the auditory system. The inferior colliculus (IC) has been shown to display age-related changes including decreased gamma-aminobutryic acid (GABA) levels, decreased glutamate decarboxylase levels, and decreased binding by GABAB receptors, as well as rearrangement of axon terminals in aging Fischer 344 (F344) rats. Age-related physiological changes have also been noted in the ICs of C57 and CBA mice. 2. Given the age-related alterations in the inhibitory neurotransmitter system, we hypothesized that aged F344 rats would show alterations in the physiological response properties of their IC neurons due to an imbalance in the relative levels of inhibition and excitation affecting the neuronal firing. 3. In vivo extracellular single-unit recordings were made from 297 IC neurons in ketamine/xylazine-anesthetized aged (24 mo) F344 rats. Locations of recorded units were determined from the electrode track marks and horseradish peroxidase marks. Results were compared with those obtained from young adult (3 mo) animals. 4. Average threshold increased from 25.4 dB SPL in young rats to 56.1 dB SPL in aged rats. 5. Although there was a reduction in the percentage of units recorded at either extreme of the frequency range in aged animals, the characteristic frequency (CF) range and mean did not differ between the two groups. 6. For the IC as a whole, no differences were noted in spontaneous activity, first spike latency, dynamic range, percentage of units with nonmonotonic contralateral CF tone rate/intensity functions (RIFs), or percentage of units sensitive to change in CF tone presentation rate. 7. In aged rats, a higher percentage of units was poorly responsive to auditory stimulation. 8. In the aged rat, there was a 12% reduction in the maximum discharge rate, a 12% increase in the percentage of units classified as onset in their temporal response pattern, and an 18% increase in the breadth of the isointensity functions at 30 dB above threshold. 9. Age-related changes in the central nucleus of the IC (CIC) frequently differed from those observed in the external cortex of the IC (ECIC). The percentage of units classified as having nonmonotonic contralateral tone RIFs decreased with age in the CIC but increased with age in the ECIC, and the percentage of units classified as onset in their temporal response pattern increased with age in the CIC but did not change with age in the ECIC. 10. The results of this study support the hypothesis that there is an age-related shift to higher intensities in the working range of most CIC units along with a small, selective deficit in inhibitory processing. When considered in conjunction with the mouse aging studies conducted by other researchers and with the results of a similar study of single units in the visual system (lateral geniculate nucleus) of young and aged rhesus monkeys, these results suggest that compensatory mechanisms are highly active in sensory systems as animals age. Despite deficits that lead to reduced input to the IC and neurochemical changes affecting neurotransmitter levels, IC neurons in aged rats are able to respond to most simple auditory stimuli in a fashion quite similar to that observed in young rats.

scholarly journals Aging Impairs Endocytic Capacity Of Splenic Dendritic Cells From Dark Agouti Rats And Alters Their Response To TLR4 Stimulation

2015 ◽  
Vol 65 (1) ◽  
pp. 30-55 ◽  
Author(s):  
BUFAN Biljana ◽  
STOJIĆ-VUKANIĆ Zorica ◽  
DJIKIĆ Jasmina ◽  
KOSEC Duško ◽  
PILIPOVIĆ Ivan ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Autoimmune Diseases ◽  
Relative Proportion ◽  
Dark Agouti ◽  
Aged Rats ◽  
Adult Rats ◽  
Young Rats ◽  
Age Related ◽  
Age Related Changes

Abstract The study was undertaken considering: i) that relative proportion of distinct subsets of splenic dendritic cells (DCs) is strain-specific and predictive for the susceptibility to autoimmune diseases; ii) age-related changes in endocytic, allostimulatory and polarizing capacity of splenic OX62+ DCs from Albino Oxford rats (relatively resistant to Th1/Th17-mediated diseases) and iii) strain specificities in age-related changes of mouse DCs. To ascertain whether there are strain specificities in age-related rat DC changes, we examined the influence of aging on OX62+ DCs from Dark Agouti (DA) rats prone to Th1/Th17-mediated autoimmune diseases. The study provided additional evidence that the predominance of CD4-cells within OX62+ DCs from young adult rats correlates with their susceptibility to Th1/Th17-mediated diseases. Consistently, lipopolysaccharide (LPS)-matured DCs from 3-month-old (young) rats exhibited Th1 driving force when co-cultured with allogeneic CD4+ T cells. This most likely reflected enhanced TNF-α and iNOS expression. Comparing with young rats, OX62+ DCs from 26-month-old (aged) rats showed: i) diminished endocytic capacity; ii) impaired ability to mature in vitro upon LPS stimulation (as indicated by lower MHC II, CD86 and CD40 surface expression), which is consistent with the increase in their IL-10 production, and iii) diminished allostimulatory capacity and loss of Th1-driving capacity in the mixed lymphocyte reaction. The latter, probably, reflected greater IL-10 production by LPS-stimulated DC from aged rats, as well as lower CD40 density on their surface. Overall, our findings suggest that aging might affect DA rat capability to mount an efficient Th1 immune response, and consequently susceptibility to Th1/Th17-mediated pathology.

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