Estrogen and thymic hormone interactions in the female mouse.
Allen. L S LS; McClure. J E JE; Goldstein. A L AL; Barkley. M S MS; Michael. S D SD
Key Findings
- TSN5 (containing thymosin‑alpha‑1) at 4 mg/kg advanced vaginal opening and increased estrogen in female mice
- A single estradiol injection reduced thymus weight and caused a short‑term drop in circulating thymosin‑alpha‑1
- Thymosin‑alpha‑1 levels decline with age and after prolonged lack of a thymus
- Early‑life thymectomy delayed puberty, while later removal had no effect
Practical Outcomes
- The study suggests thymosin‑alpha‑1 might influence estrogen and puberty timing, but the mouse model and high doses limit direct use. Biohackers should view this as basic science, not a ready‑to‑apply protocol, and await human data before considering supplementation for hormonal effects.
Summary
In mice, giving a thymus‑derived peptide mix (TSN5) sped up puberty signs and raised estrogen, while giving estrogen lowered thymus size and temporarily dropped the peptide thymosin‑alpha‑1 in the blood. The peptide levels naturally fall with age and after the thymus is removed. These results hint that the thymus and ovaries talk to each other, but the work is in mice and uses very high doses, so it doesn’t give clear guidance for people.
Abstract
This study showed that there are relationships between thymic and adrenal/ovarian endocrine actions. A 4 mg/kg dose of thymosin fraction 5 (TSN5) advanced vaginal opening and elevated estrogen levels. Single estradiol benzoate (EB) injections decreased thymus weight and caused a transient reduction in circulating plasma levels of thymosine alpha 1 (TSN alpha 1), a peptide component of TSN5. Circulating estrogen levels were elevated when TSN alpha 1 levels were undetectable. Also, TSN alpha 1 levels decreased with age and after a prolonged athymic state. The thymus was shown to involute after a single TSN5 injection, suggesting the existence of a negative hormonal feedback on the thymus. Additionally thymectomy at 3 days of age was shown to delay vaginal opening while thymectomy at 30 days of age failed to produce any significant effect on reproductive maturation. Although much research is still needed, our results provide additional evidence of a relationship between the endocrine thymus and ovary.
Study Information
pubmed
1984
10.1016/0165-0378(84)90039-1
48
28