【Animal modeling】-Sex differences in peripheral blood and immune cell phenotypes in SD rats in the aging process

  Objective To compare and analyze the gender differences of immune cell typing indexes in peripheral blood and immune organs of SD rats of different months of age.

  Methods 12-month-old SD rats and 2-month-old SD rats, half male and half male, were used to detect peripheral blood cell count and classification, organ index, peripheral blood and spleen immune cell typing, and spleen T cell P16 expression, and the results were compared. Gender differences were compared.

  Results There was no gender difference in the detection indicators of young rats. The results of peripheral blood count and classification showed that compared with young rats, the leukocytes of the aged female rats decreased; the erythrocytes of aged male rats and aged female rats increased, both of which had gender differences; the aged male rats and aged female rats had gender differences. All showed an increase in the percentage of neutrophils, a decrease in the percentage of lymphocytes, and an increase in the percentage of eosinophils, and there was no gender difference; other indicators of peripheral blood did not change significantly. The thymus index of aged female rats was lower than that of aged male rats; the spleen index of aged male rats was increased and higher than that of aged female rats. The results of flow analysis of peripheral blood immune cells showed that helper T cells, regulatory T cells and cytotoxic T cells increased in aged female rats; B cells decreased in aged female rats; natural killer cells increased in aged male rats; these indicators All have gender differences. The results of spleen lymphocyte typing showed that CD3+ increased and CD45RA+ decreased in aged female rats. The expression of P16 in spleen T cells was increased in all aged rats, and there was no gender difference.

  Conclusion In this study, there is no gender difference in the indicators of the young rats, but in the aged rats, the peripheral blood white blood cell and red blood cell counts, the percentage of neutrophils and monocytes; the index of immune organs; regulatory T cells in the analysis of immune cell typing. , Cytotoxic T cells, natural killer cells, B cells, CD3 positive cells and other indicators changes have gender differences. It suggests that the homeostasis of the immune system of aged rats is out of balance, and there are gender differences in some indicators of aged and sexual changes. The results of this study provide basic data on the effect of gender on aging for the study of geriatric diseases and aging animal models.