The Regulation Of Lymphocyte In Mice Lymphatic Organs By Estradiol And Progesterone

Objective: The mice with ovariectomy (OVX), who were treated with estradiol benzoate (EB), hydroxyprogesterone caproate(HPC) and the mixture of them respectively, were evaluated for lymphocyte count and morphological changes in lymphatic organs and peripheral leukocyte and lymphocyte count.Methods: Kunming ovariectomized female mice were treated with EB, HPC, and the mixture of them at the normal dose respectively. Another 12 ovariectomized female mice with sesame oil as contrast (OVX). There was a intact normal group (INT) as the control. Injections of hormone were performed at 5-day intervals from 40 to 190 days of age, which were 30 times totally. Cell density of T and B lymphocyte in thymus, spleen and lymph node were detected with MIAS—2000. Not only the area of T and B lymphocyte were examined under a light microscope, but also the ultrastructure of them were observed under an electronic microscope (EM). In addition, peripheral leukocyte and lymphocyte were counted.Results: There was no effect on the population of lymphocytes in the cortex of thymus gland among the five groups. Compared with INT group, HPC group and OVX group had a higher cell density of mature T lymphocyte in the medulla of thymus gland. In contrast, in EB group there was a significant reduction of medulla where cells were thin and some were replaced with adipose tissue markedly.With regard to T cell density in periarterial lymphatic sheath (PALS) of thesplenic white pulp and B cell density in splenic corpuscle, mixture of EB and HPC group had lowest T cell density and highest B cell density, while HPC had highest T cell density and a most dramatic decrease in B cell density. There was no difference between EB group and mixture of EB and HPC group. Moreover, T cell density in OVX group was enhanced significantly inferior to HPC group. Under the observation of light microscope, there was no significant difference in the periarterial lymphatic sheath (PALS) in the INT, OVX+EB.HPC and OVX+EB groups. However, significant thicken PALS was observed in the OVX+HPC and OVX groups. The greatest change in spleen corpuscle was found in OVX+EB group, such as significantly activated spleen corpuscle, increased B lymphocyte area and number. In contrast, there were very few spleen corpuscle and lower B lymphocyte density in the OVX+HPC and OVX groups.There was no significant difference in T and B lymphocyte densities in the paracortical region of the lymph nodes in both OVX+EB and INT groups (p>0.05). The T lymphocyte density was lower in OVX+EB.HPC group than INT group. However, OVX+EB.HPC group was the only one found to have increased B lymphocyte density in the lymph nodes. In the OVX group, both of T and B lymphocyte densities were decreased. In the OVX+HPC group, the highest T lymphocyte density and decreased B lymphocyte density were observed.Under the light microscope, in the OVX+EB.HPC group, the paracortex were smaller and lymphocytes were more condensed in the lymphatic nodule than the OVX+EB and INT groups. In the OVX+HPC group, T lymphocyte area was enlarged and cells were condensed. T lymphocyte area was significantly reduced, cell density was decreased in the OVX group, along with decreased B lymphocyte number in...