Mechanism Of Local Immunoregulation In Rat Mammary Gland

To explore the regulatory mechanism of the local immunity in mammary gland during the lactatingand non-lactating periods, the changes on morphological structure and distribution of immune cells were observed in the rat with histological, histochemical and immunohistochemical techniques.The results showed: (1)Only mucosal mast cells(MMC) existed in rat mammary gland and their sizes were similar between the lactating and non-lactating periods (P>0.05). The mast cells in lactating mammary gland were different in staining because some of them were degranuling. The MC numbers per field (by 40x object lens, the following is the same) were 2.8±0.9 and 9.9±1.8 in two stages. The mast cells remarkably increased during the non-lactating period (P<0.01). (2)Mammary gland lymphocyte numbers varied from 11.7±2.1 during the lactating period to 19.6±3.0 during the non-lactating period (PO.01). The ANAE+T cell numbers varied from 6.7±0.2 during the lactating period to 11.4±0.6 during the non-lactating period (PO.05). (3)Shape of CD4+ and CD8+T cell didn't change during two periods. CD4+T cell numbers varied from 3.1±0.8 to 4.4±0.4 and CD8+T cell numbers varied from 1.3±0.3 to 2.7±0.5. The former hadn't significant difference (P>0.05) but the latter significantly increased (PO.05). CD4+/ CD8+ ratio reduced from 2.4 during the lactating period to 1.6 during the non-lactating period. ㊣n peripheral blood, the lymphocyte numbers varied from 1.6±0.4 during the lactating period to 1.5±0.7 during the non-lactating period (P>0.05) and the ANAE+T cell numbers varied from 1.1±0.3 to 0.8±0.2(P>0.05). The mammary gland plasmacyte numbers were 1.3±0.3 during the lactating period and 1.3±0.4 during the non-lactating period. They were nearly equal to each other (P>0.05). While the IgA+plasmacyte number were 1.2±0.2 during the lactating period and dropped to 0.8±0.1 during the non-lactating period (P<0.05).In conclusion, the local immunity in the rat mammary gland was of characteristics of mucosal immunity. The immune level obviously varied during the physiological cycle. The local immunity in mammary gland was relatively independent to the organismal immunity and was enhanced during the lactating period.