Ageing thymus

The decline in immune function may pardy depend on a deficiency of coenzyme Q, a group of closely related quinone compounds (ubiquinones) that participate in the mitochondrial electron transport chain (49). Concentrations of coenzyme Q (specifically coenzyme Q q) appear to decline with age in several organs, most notably the thymus. 

Thymus ALuticJnmi, the so-called Spanish wuod marjoram, yields an oil of thyme which has been examined recently hy Dorrousoro,- It ban a bright vnllow colour, turning darker with age, and a camphoracc-... 

Oughton JA, Pereira CB, DeKrey GK, et al. 1995. Phenotypic analysis of spleen, thymus, and peripheral blood cells in aged C57BL/6 mice following long-term exposure to... 

A decline in immunologic function with increasing age has long been recognized. Thus, older individuals are more prone to various infectious diseases, autoimmune phenomena, amyloidosis, myelomatosis, chronic lymphoprolifera-tive disorders, and various forms of cancer. This decreased responsiveness of the immune system is primarily related to thymus-derived (T) lymphocytes (B17). However, B-lymphocytes are also affected since there is frequently a decreased... 

Eriodictyol (flavonoid) Eriodictyon californicum (Hydrophyllaceae), Ocimum basilicum, Origanum mlgare. Thymus vulgaris (Lamiaceae), Citrus paradisi (Rutaceae) i AGEs... 

The restoration of immune functions of the aged individuals is possible and might be beneficial for them to cope with various diseases associated with aging (Hirokawa, 1997). Physiological thymic atrophy is controlled by both extrathymic and intrathymic factors and is not a totally irreversible process. Tlie process of thymic atrophy might be explained by a further understanding of the relationship between the neuroendocrine and the immune systems (Hirokawa et al., 1994). Although the most obvious age-related structural alteration of the immune system occurs in the thymus, the role of thymic involution in immunosenescence is still not well understood. 

In a cohort of apparently healthy and well-nourished elderly women, total T (CD3 ), T-helper (CD4 ), or T-cytotoxic (CD8 ) cell number, NK cell number, cytotoxicity, phagocytosis, and subsequent oxidative burst were similar to values in young women. However, they had lower T-cell proliferation responses and significantly reduced response to phytohemagglutinin (Krause et al., 1999). T-cells show the largest age-related differences in distribution and function with aging with thymus involution as the apparent underlying cause (Shinkai et al., 1998). 

Fahris N, Mocchegiani E, Provinciali M. Plasticity of ncurocndocrine-thymus interactions during aging. Exp Gerontol 1997 32 415 429. 

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