[Immunomodulatory effects of thymopentin under acute and chronic inflammations in mice]

The effects of thymopentin, a synthetic analogue of the active center of the thymus hormone thymopoietin, on the immune status of mice with two different models of inflammation induced by injection of lipopolysaccaride (LPS) from gram-negative bacteria were studied. Acute inflammation was induced by a single injection of LPS in a dose of 250 microg/100 g of body weight, and chronic inflammation (sepsis) was modeled by a daily injection of LPS for 11 days with a gradual increase in the dose range from 25 to 250 microg/100 g of body weight. Under acute inflammation, a preliminary injection of thymopentin did not induce any additional stimulation in cytokine production increased by LPS. On the contrary, whereas the chronic introduction of LPS was characterized by a depressed production of several cytokines, thymopentin produced an immunostimulating effect. Thus, an increase in the production of nitric oxide, interferon-gamma, and Hsp70 was demonstrated. In addition, a more effective restoration of the number of thymus cells, as well as an increase in macrophage tumor necrosis factor-alpha production were observed after repeal of LPS + hormone injections. The results show that preliminary application of thymopentin promotes the regulation of immune cell activity under acute and chronic inflammation.