THE DENSITY AND DISTRIBUTION OF FOLLICULAR DENDRITIC CELLS IN RAT POPLITEAL LYMPH-NODES - A DECREASE IN THEIR DENSITY AND A CHANGE IN THEIRDISTRIBUTION AFTER STIMULATION
H. Sato et M. Dobashi, THE DENSITY AND DISTRIBUTION OF FOLLICULAR DENDRITIC CELLS IN RAT POPLITEAL LYMPH-NODES - A DECREASE IN THEIR DENSITY AND A CHANGE IN THEIRDISTRIBUTION AFTER STIMULATION, Histology and histopathology, 10(4), 1995, pp. 795-802
To determine whether follicular dendritic cells (FDCs) increase after
stimulation, and also to confirm the widely accepted finding that the
density of FDCs in the light zone is higher than that in the dark zone
, we examined the density of FDCs in lymph follicles of rat popliteal
lymph nodes. Rats aged five weeks were stimulated by injection of shee
p erythrocytes, and then examined 10 days later. Unstimulated rats wer
e also examined. After embedding in paraffin, the removed lymph nodes
were immunostained with anti-S-100 protein antibody as a marker of rat
FDCs. The density of FDCs was determined by measuring the area of the
lymph follicle and counting the number of S-100 protein-positive cell
s within it. The density of FDCs in the lymph follicles of stimulated
rats was found to be significantly lower than in 5-week-old and unstim
ulated rats. The density of FDCs in the light zone was similar to that
in the dark zone when germinal center bordering cells (GCBCs), distri
buted at the border between the dark zone and the adjacent corona, wer
e counted as FDCs. We conclude that the density of FDCs in lymph folli
cles decreases after stimulation, and suggest that FDCs have no or onl
y very slight proliferative activity under normal conditions. Investig
ators may need to consider GCBCs in order to understand how FDCs diffe
rentiate.