Thymalfasin raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-06-08. Anything still debated is marked as such rather than presented as settled.
Early work on thymic extracts in the 1960s described a heat-stable acidic fraction containing many polypeptides. Separation of that mixture yielded individual components, and thymosin alpha-1 was named as one of them on the basis of assays for T-cell activity. The first preparations came from calf thymus, while subsequent research and clinical material has been chemically synthesized. Nomenclature in older papers is inconsistent, and the same peptide sometimes appears under different designations, which complicates literature searches.
Most published studies on thymosin alpha-1 report changes in immune measurements rather than clinical outcomes, and findings differ across designs and populations. Whether the peptide signals through one defined receptor or through several less specific interactions remains an open question. Its reported circulation half-life of a few hours complicates comparison of dosing schedules across trials. Mechanistic claims are frequently drawn from isolated cell cultures, and how far those results extend to whole organisms is unresolved.
胸腺素α1（thymosin alpha 1，Tα1）是一种由28个氨基酸组成的酸性肽，N端被乙酰化，分子量约为3108道尔顿。该肽最早从牛胸腺组织提取物中分离，属于胸腺素组分5的一个成分。其序列在不同哺乳动物中高度保守，提示其具有基本的生物学功能。名称中的“α1”指其在电泳中的迁移位置，并非表示亚型编号。它既存在于胸腺，也存在于脾脏和淋巴结等免疫组织。
20世纪70年代，研究者从胸腺提取物中纯化出多种小肽，Tα1是其中被较早表征的一种。最初的制备依赖组织匀浆和层析步骤，产量低且成分复杂。随着固相肽合成技术成熟，实验室和工业界能够生产与天然序列一致的合成版本。合成肽的纯度可达95%以上，并可通过反相高效液相色谱和质谱进行鉴定。这一转变使研究不再依赖动物胸腺来源。
市售的胸腺素α1通常以冻干粉形式提供，溶解后用于注射。其氨基酸组成包括多个酸性残基，因此在中性pH下带负电荷。该肽可溶于水和生理盐水，但在有机溶剂中溶解度有限。储存条件通常为冻干状态下负20摄氏度，溶解后需冷藏并避免反复冻融。常见的同义词包括胸腺肽α1、thymalfasin和Tα1。
| Property | Value | Notes |
|---|---|---|
| Class | Synthetic peptide | 28 residues; not a small-molecule compound |
| Molecular mass | About 3,106 Da | Monoisotopic mass of the unmodified chain |
| N-terminal group | Acetylated serine | Present in both native and synthetic forms |
| Secondary structure | Disulfide-constrained loop | One bridge between two cysteine residues |
| Typical source | Solid-phase synthesis | Early isolates came from bovine thymus extracts |
Thymosin alpha-1 is a synthetic peptide of 28 amino acid residues that corresponds to a naturally occurring fragment first isolated from thymus tissue. Its chain is acetylated at the amino terminus, a modification that shields the peptide from rapid cleavage by aminopeptidases. The molecule carries a net negative charge at physiological pH and dissolves freely in water. Researchers classify it as an immune-modulating agent rather than a classical hormone, because it acts on several cell types of both the innate and the adaptive immune system.
The peptide was identified during work in the 1970s on thymosin fraction 5, a partially purified extract of calf thymus. Investigators separated that mixture and characterized individual components, one of which they named thymosin alpha-1. The same compound later received the international nonproprietary name thymalfasin. Commercial material is produced by solid-phase peptide synthesis rather than by extraction, so synthetic and natural forms share an identical sequence. Naming conventions vary across the literature, and readers should distinguish the alpha-1 peptide from other thymosins that have unrelated sequences and functions.
Thymosin beta-4 is a separate 43-residue peptide that binds actin and participates in cell migration; it shares no sequence similarity with thymosin alpha-1 despite the common family name. Other preparative materials, such as thymosin fraction 5 and thymopoietin, contain distinct mixtures or peptides. The shared thymosin label reflects the tissue of origin used in early purification, not a common structural core. Treating these molecules as interchangeable is a frequent source of confusion in laboratory reports and in popular summaries alike.
Thymosin alpha 1 is a short peptide of 28 amino acid residues that derives from the amino terminal region of a larger precursor protein known as prothymosin alpha. The peptide carries an acetyl group on its first residue and contains no disulfide bonds or carbohydrate chains. Its sequence is highly conserved across mammalian species, which is one reason laboratories treat it as a molecule with a defined and reproducible structure rather than a variable tissue extract. The name follows an early naming convention for thymus-derived fractions and does not imply that the peptide acts as a hormone in the classical endocrine sense.
Biologically, the peptide is studied mainly in the context of immune cell development and regulation. It is produced in the thymus and in several other tissues, and it appears to influence the maturation and activity of T cells and other immune populations. Laboratory work describes effects on cytokine production, on the balance between T cell subsets, and on the function of dendritic cells. Much of this evidence comes from cell culture and animal models, so the extent to which the same pathways operate in humans remains an open question.
Cholesterol has 256 stereoisomers that arise from its eight stereocenters. Only two of the stereoisomers have biochemical significance: nat-cholesterol and ent-cholesterol (for natural and enantiomer, respectively). The only cholesterol stereoisomer to occur naturally is nat-cholesterol.
=== Printed === Bönisch, Susanne (1996). Natural Healing for Cats. Sterling Publishing Company. ISBN 978-0-8069-8122-2. Casal, Margret; Jezyk, Peter; Giger, Urs (1996). "Transfer of Colostral Antibodies From Queens to Their Kittens". American Journal of Veterinary Research. 57 (11): 1653–1658. doi:10.2460/ajvr.1996.57.11.1653. PMID 8915447. Crowell-Davis, Sharon (2005). "Cat Behaviour: Social Organization, Communication and Development". The Welfare of Cats. Animal Welfare. Vol. 3. Rochlitz. pp. 1–22. doi:10.1007/1-4020-3227-7_1. ISBN 1-4020-3226-9. Guilford, Grant (1994). "Nutritional Management of Gastrointestinal Tract Diseases of Dogs and Cats". Journal of Nutrition. 124 (12 Suppl): 2663S–2669S. doi:10.1093/jn/124.suppl_12.2663S. PMC 7107501. PMID 7996263. Heath, Sarah (2005). "Behaviour Problems and Welfare". The Welfare of Cats. Animal Welfare. Vol. 3. Rochlitz. pp. 91–118. doi:10.1007/1-4020-3227-7_4. ISBN 1-4020-3226-9. McHattie, Grace (1993). That's Cats! A Compendium of Feline Facts. David & Charles. ISBN 978-0-7153-0126-5. Messonnier, Shawn (2010). Natural Health Bible for Dogs & Cats: Your A-Z Guide to Over 200 Conditions, Herbs, Vitamins, and Supplements. Crown/Archetype Publishing. ISBN 978-0-307-55860-2. Olson, Patricia; Kustritz, Margaret; Johnston, Shirley (2001). "Early-age Neutering of Dogs and Cats in the United States". Journal of Reproduction and Fertility Supplement. 57: 223–232. PMID 11787153. Poirier, Frank; Hussey, Kaye (1982). "Nonhuman Primate Learning: The Importance of Learning from an Evolutionary Perspective".
Thatcher wrote "I will not tolerate failure in this area" in the margin of the report and in the summer of 1982 a new committee was set up under Willie Whitelaw, only to come to much the same conclusion (The eventual solution, a "poll tax", was rejected both by the Green Paper and by Whitelaw's committee). Heseltine resisted demands by Leon Brittan, the Chief Secretary to the Treasury with whom he already enjoyed a somewhat antagonistic relationship, that central government have power to cap the spending of local authorities. He argued that the worst offenders were the large metropolitan counties (which, ironically, he had helped to create a decade earlier) and that the simplest solution was simply to abolish them. In the event, the 1983 manifesto, after Heseltine had moved to his next job, committed the Conservatives both to abolition of the metropolitan boroughs and to rate capping. When Heseltine objected after the election, Thatcher gave him "one of the most violent rebukes I have ever witnessed in Cabinet" according to Jim Prior, who believed that the issue helped fuel the hostility between Heseltine and Thatcher and Brittan, which would later exhibit itself as the Westland Affair. In opposition, in the late 1970s, Heseltine had been committed to reducing central government control over local government. In the 1980s, the opposite happened, with no less than 50 Acts of Parliament reducing the powers of local government. In Crick's view, although he opposed both rate capping and the poll tax, the overall trend towards centralisation was too strong for him to resist.
Sources: en.wikipedia.org
=== Cardiovascular health === While AM could be an important biomarker for bacterial infections like sepsis, AM has diminished value in its utility for cardiovascular diseases (CVD), attributable to its minimal increase in these conditions and reduced half-life. AM is associated with controlling vascular integrity, blood pressure, and general cardiovascular function. Since AM has been noted for its exacerbated levels in intense diseases with an elevated concern for mortality, AM could still have some value as a predictive biomarker of harmful clinical consequences for an array of cardiovascular illnesses. AM has conservatory effects against arteriosclerosis and vascular harm. Extended AM administration or hyper-expression of its target gene in rodent model organisms diminishes vascular hyperplasia, fatty streak construction, and intimal expansion. AM also has angiogenic characteristics, leading to organ and tissue maintenance by reducing the risk of ischemic diseases. AM binds to particular receptors like calcitonin gene-related peptide (CGRP) receptors, which affects the cardiovascular system by contributing to vasodilation as well as elevated heart rate and blood pressure.
=== Somatostatin analogs === Octreotide is an analog of the peptide hormone somatostatin, which inhibits the production of the growth hormone as well as numerous peptide hormones of the gastrointestinal system, including insulin, glucagon, pancreatic polypeptide, gastric inhibitory polypeptide, and gastrin. Octreotide is used for suppression of the hormonal syndromes which accompany several pancreatic islet cell tumors, including the Zollinger-Ellison syndrome of gastrinoma and the chronic hypoglycemia of insulinoma. It is also effective in suppression of the carcinoid syndrome, caused by advanced or extra-gastrointestinal carcinoid tumors. Octreotide may also be used for treatment of severe diarrhea caused by 5-fluorouracil chemotherapy or radiation therapy.
=== Bronze Wolf Award === WOSM's Bronze Wolf Award is given for exceptional services to the international Scout Movement. It was first awarded to Robert Baden-Powell by a unanimous decision of the committee on the day the award was instituted in 1935.
Sources: en.wikipedia.org
Its sequence corresponds to the amino-terminal portion of prothymosin alpha, a larger protein present in many cell types. The isolated 28-residue peptide is a fragment of that protein rather than a separately encoded molecule, and laboratory material is produced by synthesis.
The single bridge between two cysteine residues holds the chain in a folded loop that influences its shape and its behavior in solution. Loss of the bridge through reduction or oxidation shifts chromatographic retention and is tracked during stability work.
It is a defined 28-residue sequence derived from a larger precursor, whereas many other thymic preparations are mixtures of several polypeptides. Its acetylated amino terminus and single disulfide bridge distinguish it chemically from unrelated thymic extracts.
它不是经典的内分泌激素，而是一种免疫调节肽。其作用主要通过局部免疫细胞间的信号传递实现，而非经血液循环作用于远隔器官。