Effects of thymosin alpha1 on the development of amoeboid microglial cells in the corpus callosum of neonatal BALB/c and athymic mice.
Htain. W W WW; Leong. S K SK; Yuen. R R; Ling. E A EA
Key Findings
- Thymosin‑alpha‑1 injections cut the number of supraventricular amoeboid microglial cells by about 27% in athymic mice and 37% in normal BALB/c mice.
- A portion of the remaining microglia became more ramified (branched) after treatment, while others stayed amoeboid but showed fewer filopodia.
- Plasma cortisol rose significantly after thymosin‑alpha‑1 administration, and the rise correlated with the drop in microglial cell numbers.
Practical Outcomes
- The study shows that thymosin‑alpha‑1 can influence brain immune cells and stress hormones in newborn mice, but it provides no clear guidance for human dosing or benefits. For biohackers, the main takeaway is that using this peptide could potentially affect microglial activity and cortisol, so any self‑experimentation should be approached with caution and is not currently supported by human data.
Summary
In newborn mice, giving thymosin‑alpha‑1 reduced the number of a certain type of brain immune cell (amoeboid microglia) and raised cortisol levels in the blood. Some of the remaining cells changed shape to look more like normal, branching microglia.
Abstract
The present study investigated the effects of intraperitoneal injections of thymosin alpha1 on the supraventricular amoeboid microglial cells (SAMC) in the newborn athymic and normal BALB/c mice. The microglial cells labelled by the lectin GSA I-B4 and the antibody Mac-1 showed a 27% reduction in number in the athymic mice receiving thymosin alpha1 injections compared with those receiving vehicle injections, and a 37% reduction in BALB/c mice receiving thymosin alpha1 injections compared with those receiving vehicle injections. Some of the SAMC in both BALB/c and athymic mice receiving thymosin alpha1 injections became ramified, while the remainder still exhibited their normal amoeboid appearance with few filopodial processes. Ultrastructurally, the lectin reaction product was confined to the plasma membrane and some cytoplasmic vacuoles of labelled SAMC. In both BALB/c and athymic mice, some labelled microglial cells became slender or elongated after thymosin alpha1 injections. Also their cytoplasm was reduced and contained fewer organelles. Radioimmunoassay of the plasma of thymosin alpha1 and vehicle-injected mice showed that there was a significant increase in the cortisol level in BALB/c (P < 0.01) and athymic (P < 0.001) mice 5 days after thymosin alpha1 injections, compared with that of the control mice. The results point to a strong correlation between the reduction of SAMC and the increased level of plasma cortisol. Supporting this is the fact that cortisol is known to suppress the production of monocytes considered to be the precursors of amoeboid microglia.
Study Information
pubmed
1997
1997-04-25T00:00:00.000Z
10.1016/s0006-8993(97)00108-x