Introduction
The thymopentin is a small peptide consisting of 5 amino acid residues (Arg-Lys-Asp-Val-Tyr) from thymosin. It has the same biological activity as thymogen, which can regulate the imbalance of the body and enhance the body's immunity. The thymopentin also mediates the proportion of T lymphocyte subsets. Thymopentin has a two-way immune regulation function, which is helpful for improving the prognosis of patients with severe hepatitis. It is used to improve the immune function caused by radiotherapy and chemotherapy in patients with malignant tumors.
Pharmacologic action
The occurrence and development of viral hepatitis B is closely related to the imbalance of immune function. The pathogenesis of chronic severe hepatitis B is a cellular immune response, mainly CD8+ cytotoxic T cell-mediated cytotoxicity caused by primary liver injury. At present, many scholars believe that the peripheral CD4+/CD8+ ratio imbalance in patients with chronic severe hepatitis is related to its pathogenesis. Thymopentin prevents liver tissue inflammation by inducing and promoting T cell differentiation, proliferation and maturation, regulating the proportion of T cell subsets, and making CD4+/CD8+ tend to normal to correct abnormal immune function in patients with chronic severe hepatitis B. Necrosis is further aggravated and its prognosis is improved.
Function
Thymopentin is a polypeptide synthesized according to the amino acid sequence of the thymopoietin II immunologically active center, and has a bidirectional regulation function of the immune system. Thymopentin treatment can effectively improve the survival rate of patients with severe hepatitis in the early and middle stages, but has no obvious effect on patients with advanced hepatitis. It suggests that early application of thymopentin may prevent patients with severe hepatitis from continuing to worsen and improve the prognosis of patients with severe hepatitis.
Pharmacokinetics and metabolism
After intramuscular injection of thymopentin solution, the peak concentration was reached in 10 minutes. The peak concentration was (15.17 ± 2.17) μg/mL, and then quickly eliminated. After 12 hours, the blood drug concentration was below the limit of quantitation and could not be detected. Thymopentin degrades rapidly in the body, with a half-life of only 30 s. It is difficult to detect thymopentin in the blood by conventional means. Therefore, a method for determining the pharmacokinetics of FITC-labeled thymopentin in plasma was established.
References:
1. Zhang Xuqing, Wang Yuming, et al. Efficacy evaluation of thymopentin in the treatment of chronic severe hepatitis B. ACTA ACADEMIAE MEDICINAE MILITARIS TERTIAE Vol.25, No .22
2. Huang Zicun, Yang Jian, Zhou Jianliang, et al. Immunomodulation study of Zidaxian in the treatment of severe hepatitis. Chinese Journal of Integrated Traditional and Western Medicine on Hepatology, 1999, 9(4): 10 -11
3. Jiao Yuhuan 1, Sun Kaoxiang, et al. Preparation of thymopentin sustained-release polycystic liposomes and preliminary study on pharmacokinetics of rats. Acta Pharmaceutica Sinica 2008, 43(7): 756-760
