[Quantitative changes in the lymphoid cell populations of the skin and regional lymph node after exposure to whole-body deep hypothermia].

The effect of general deep hypothermia on quantitative changes in populations of lymphoid cells in the skin and regional lymph node (LN) was studied in experiments in 20 male albino rats. The narcotized animals were cooled up to 18 degrees C of rectal temperature, kept at this temperature during 2h and then warmed up to 37 degrees C. Early terms of the posthypothermia period were characterized by less density of the population of intraepidermal lymphocytes and a simultaneous increase of their amount in the papillary and reticular layers of the derm without any changes in the hypodermis. Subsequently the lymphocyte population density in the derm was decreased, a little later their amount in the hypodermis was decreased. A simultaneous increase of the amount of lymphocytes took place in the area of postcapillary venules of the paracortical zone of LN. At the late post-hypothermal period the quantity of lymphocytes in the skin was restored. In the B-zones of LN less sizes of lymphoid nodules were noted as well as decreased population density (PD) of mitotically dividing cells, blasts and lymphocytes with pyknotized nuclei. A simultaneous increase of PD of plasmocytes took place in cerebral cords and elevated activity of alkaline phosphomonoesterase was noted in these cells. At the late posthypothermia period the area occupied by cerebral cords on the section was increased and correspondingly the area occupied by the cortical substance was decreased. A conclusion is made that resistant properties of the skin are activated after hypothermia procedures.