Age-related changes in liver, gall bladder and 
pancreas

Although a reduced liver size in elderly people has long been recognized from post-mortem studies, these studies do not allow the separation of true ‘age-related’ differences from the effects of premorbid illness, and death. An age-related effect was confirmed however by an in vivo study which measured liver size by ultrasound scanning of healthy individuals. This demonstrated a significant negative correlation between age and liver volume, with volumes being 28% lower in individuals above the age of 65 compared with those under 40 years of age.

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Age-related changes in Tau and Autophagy in human brain in the absence of neurodegeneration

10.1101/2021.08.21.456385 ◽

2021 ◽

Author(s):

Amritpal Mudher ◽

Shreyasi Chatterjee ◽

Megan Sealey ◽

Eva Ruiz ◽

Chrysia Maria Pegasiou ◽

...

Keyword(s):

Therapeutic Potential ◽

Phosphorylated Tau ◽

Post Mortem ◽

Cognitively Normal ◽

Age Related ◽

Normal Individuals ◽

Drosophila Model ◽

Resected Tissue ◽

Age Related Changes

Tau becomes abnormally hyper-phosphorylated and aggregated in tauopathies like Alzheimers disease (AD). As age is the greatest risk factor for developing AD, it is important to understand how tau protein itself, and the pathways implicated in its turnover, change during aging. We investigated age-related changes in total and phosphorylated tau in brain samples from two cohorts of cognitively normal individuals spanning 19-74 years, without overt neurodegeneration. One cohort utilised resected tissue and the other used post-mortem tissue. Total soluble tau levels declined with age in both cohorts. Phosphorylated tau was undetectable in the post-mortem tissue but was clearly evident in the resected tissue and did not undergo significant age-related change. To ascertain if the decline in soluble tau was correlated with age-related changes in autophagy, three markers of autophagy were tested but only two appeared to increase with age and the third was unchanged. This implies that in individuals who do not develop neurodegeneration, there is an age-related reduction in soluble tau which could potentially be due to age-related changes in autophagy. Thus, to explore how an age-related increase in autophagy might influence tau-mediated dysfunctions in vivo, autophagy was enhanced in a Drosophila model and all age-related tau phenotypes were significantly ameliorated. These data shed light on age-related physiological changes in proteins implicated in AD and highlights the need to study pathways that may be responsible for these changes. It also demonstrates the therapeutic potential of interventions that upregulate turnover of aggregate-prone proteins during aging.

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Age-related changes in in vitro and in vivo survival of murine CFU-S and CFU-c

Mechanisms of Ageing and Development ◽

10.1016/0047-6374(82)90060-4 ◽

1982 ◽

Vol 19 (3) ◽

pp. 279-287 ◽

Cited By ~ 5

Author(s):

Marvin L. Tyan

Keyword(s):

Age Related ◽

Age Related Changes

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Age-related changes in collagen synthesis and degradation in rat tissues. Importance of degradation of newly synthesized collagen in regulating collagen production

Biochemical Journal ◽

10.1042/bj2760307 ◽

1991 ◽

Vol 276 (2) ◽

pp. 307-313 ◽

Cited By ~ 120

Author(s):

P K Mays ◽

R J McAnulty ◽

J S Campa ◽

G J Laurent

Keyword(s):

Skeletal Muscle ◽

Collagen Synthesis ◽

Rat Tissues ◽

Age Related ◽

Developmental Growth ◽

Cross Links ◽

Fractional Synthesis ◽

Synthesis And Degradation ◽

Age Related Changes

During developmental growth, collagens are believed to be continuously deposited into an extracellular matrix which is increasingly stabilized by the formation of covalent cross-links throughout life. However, the age-related changes in rates of synthetic and degradative processes are less well understood. In the present study we measured rates of collagen synthesis in vivo using a flooding dose of unlabelled proline given with [14C]proline and determining production of hydroxy[14C]proline. Degradation of newly synthesized collagen was estimated from the amount of free hydroxy [14C]proline in tissues 30 min after injection. Collagen fractional synthesis rates ranged from about 5%/day in skeletal muscle to 20%/day in hearts of rats aged 1 month. At 15 months of age, collagen fractional synthesis rates had decreased markedly in lung and skin, but in skeletal muscle and heart, rates were unchanged. At 24 months of age, synthesis rates had decreased by at least 10-fold in all tissues, compared with rates at 1 month. The proportion of newly synthesized collagen degraded ranged from 6.4 +/- 0.4% in skin to 61.6 +/- 5.0% in heart at 1 month of age. During aging the proportion degraded increased in all tissues to maximal values at 15 months, ranging from 56 +/- 7% in skin to 96 +/- 1% in heart. These data suggest that there are marked age-related changes in rates of collagen metabolism. They also indicate that synthesis is active even in old animals, where the bulk of collagens produced are destined to be degraded.

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