[Age-related changes in circadian and circannual fluctuations of the immune response and the number of cells in lymphoid organs of animals: a possible connection to thymic factors].
Labunets'. I F IF
Key Findings
- Aging blunts the normal 24‑hour and seasonal peaks of thymus and spleen cell counts and antibody production in mice and rats.
- Chronic (18‑month) treatment with the thymus extract peptide thymalin increased the serum thymic factor (FTS) titer in old animals.
- Thymalin restored the autumn peak of antibody titers that is normally lost with age.
Practical Outcomes
- For biohackers interested in immune aging, this study hints that long‑term thymalin supplementation might help sustain or revive age‑related immune rhythms. However, the data are from rodents, no human dosing or safety information is provided, so any protocol would be experimental and should start with low doses and careful monitoring.
Summary
In older mice and rats, the natural daily and seasonal swings in immune cell numbers and antibody levels flatten out. Giving them the thymus‑derived peptide thymalin for many months lifted a key thymic factor in the blood and helped bring back a seasonal spike in antibodies, suggesting thymalin can partly revive age‑related immune rhythms in rodents.
Abstract
The 24-hour and seasonal fluctuations of cellularity of thymus and spleen and antibody levels in male CBA/Ca mice and Wistar rats of different ages were investigated. In adult rats (6-11 mo) the peaks of thymus and spleen cellularity were at nights and in the daytime, respectively. In young mice (3 mo) the thymus and spleen cellularity were highest in autumn and spring, respectively. The titer (log2) of hemolysines in autumn was 16 times greater than in spring. Correlations between the rhythmical changes of cellularity of thymus and spleen and between the latter and the factor thymic serique (FTS) titer were found. With age (4 month and onward in mice and 17 months in rats), the peaks of amounts of cells in thymus and of its mass in night and in autumn and of the antibodies titers in autumn were diminished. The displacement of the acrophases of indicers to other seasons was seen. In old animals the rhythm of indices became monotonous. In aging the intrasystemic relations underwent changes (new relation appeared, while the existing ones weakened or disappeared). The chronic (18 mo) administration of thymus preparation thymalin increased FTS titer and promoted the appearance of the peak of antibodies in autumn.
Study Information
pubmed
2001