Effect of glyprolins on white blood cell parameters and phagocytic activity of neutrophils in conditions of experimental hyperthyroidism

This study investigated the effects of glyproline neuropeptide compounds (selank and Pro-Gly-Pro) on the white blood cell count and phagocytic activity of neutrophils in 40 nonlinear white male rats aged 6–8 months with experimental hyperthyroidism. Experimental hyperthyroidism was simulated by intragastric administration of L-thyroxine sodium salt pentahydrate at a dose of 150 µg/kg/day for 21 days. All animals were equally divided into four groups: healthy rats (control), rats treated with L-thyroxine sodium pentahydrate (hyperthyroidism), rats treated with selank, and rats treated with Pro-Gly-Pro at doses of 200 µg/kg/day intraperitoneally for 21 days, starting one day after the last administration of L-thyroxine sodium pentahydrate. After the animals were removed from the experiment, the white blood cell count and the percentage of lymphocytes, stick, and segmentonuclear neutrophils were calculated, and the phagocytic activity of neutrophils was evaluated. In the case of experimental hyperthyroidism, neutrophilic leukocytosis with a shift to the right, lymphopenia, and decreased phagocytic activity of neutrophils were observed. Glyproline neuropeptides contributed to the correction of observed changes in white blood cell indices and phagocytic processes, which indicates the immunocorrigating effect of the test compounds. Thus, glyproline neuropeptides demonstrated pronounced immunotropic activity, which manifested in the correction of changes arising from the leukocyte count and phagocytosis processes. However, further detailed study of the pharmacological effects of neuropeptide agents on experimental hyperthyroidism is necessary.