Change in the amount of epsilon-hexosyllysine, UV absorbance, and fluorescence of collagen with age in different animal species.

The research focuses on studying how glycation and accumulation of chromophore products in collagen change with age across different animal species, including rats, mice, dogs, cats, horses, and humans. It also explores how these processes differ in varying tissues, with a particular focus on skin and aortal collagen.

Experimental Subjects and Procedure

• The study was conducted on collagen samples sourced from the skin and aorta tissues of Wistar rats, white mice, beagle dogs, cats, horses, and humans of different ages.
• These specimens were examined to determine the content of glycated products, to understand how they vary with age and across different species.
• The concept of glycation, a non-enzymatic reaction between sugars and proteins that forms glycosylated products, was a significant part of this study.

Research Findings

• The findings indicated that the process of glycation and the accumulation of chromophore products follow a nearly similar pattern in collagen samples across the studied species when ages are comparable.
• There is a notable increase in glycation and pigmented accumulation during the first 5-10 years of age.
• The extent of glycation varied across tissues, with aortal collagen showing about twice the amount of glycation than skin collagen.
• Fluorescence-assessed collagen pigmentation was comparable in both aortal and skin collagen, except in individuals aged below ten years. However, pigmentation measured through absorbance at 350 nm was lower in aortal collagen than in skin collagen.

Conclusions and Implications

• Assuming that blood glucose levels remain constant throughout an individual’s lifespan, the researchers inferred that the levels of collagen glycation could reflect the duration during which the protein was exposed to sugars.
• The exposure period is expected to be longer in older animals due to the increased cross-linking of collagen.
• The study also suggests that additional factors, such as differing rates of collagen turnover across tissues and the intensity of glycated product removal processes, should be considered when discussing collagen glycation.
• This research can enhance the understanding of aging processes in animals, including humans, and provide valuable insights into collagen-related diseases and conditions.