Studies on lymphocyte subsets in the rats received cardiac allografts

To analyse the role of lymphocyte subsets in the rats which have received cardiac allografts, DA (RTI^a) carfiac allografts were hererotopically transplanted to normal Lewis (RTI^l) recipients. Functioning DA cardiac allografts were removed at days 1, 3, and 5 post-transplantation, and infiltrating host cells were evaluated immunohistochemically using a series of anti-rat monoclonal antibodies (OX6, Ox8, W3/13 and W3/25). Absolute number of leukocytes, oernentage and absolute number of lymphocytes of the peripheral blood were enumerated at 1, 3, 5 and 7 days after transplantation. Lymphocytes obtained from the peripheral blood, cervical lymph nodes and spleen at 1, 3, 5 and 7 days after transplantation were stained by monoclonal antibodies (OX6, OX8, W3/13 and W3/25) and then enumertated by flow cytometry. The ratio of T helper to T suppresser/cytotoxic phenotype cells in host spleen pealed to 2.2±0.2 by day 1, and then it went on declining. Ratio peak occurred slightly later in host lymph nodes and peropheral blood. For lymphocyte prepatation from periphperal blood prior to staining for flow cytometric analysis, we used two methods : Ficoll-hypaque gradient separation, and the former method is much simpler than the latter method, whole blood lysis technique in lymphocyte preparation may be preferable for the analysis of lymphocyte subsets.