Trafficking of recirculating lymphocytes in the rat liver: rapid transmigration into the portal area and then to the hepatic lymph.
BACKGROUND
We have investigated how recirculating lymphocytes patrol the liver in a normal steady state.


METHODS
Thoracic duct lymphocytes of congeneic rats were intravenously transferred to host rats and donor cell trafficking in the liver and hepatic lymph was examined. Host hepatic lymph nodes (HLNs) were selectively removed, which allowed liver-derived donor cells to collect in the thoracic duct without transit in the intervening HLNs.


RESULTS
The number of donor cells in the thoracic duct lymph significantly increased over the baseline 3, 5 and 11 h after transfer in the HLN-removed, non-pretreated, and HLN-ligated (in which a lymph efflux was blocked) groups, respectively. Histologically, donor cells appeared in the portal area from 0.5 h after transfer and frequently attached to the basal lamina of portal vein both externally and internally. Three hours after transfer, a few donor cells appeared in the subcapsular sinus of HLNs.


CONCLUSIONS
The minimal transit time of rat recirculating lymphocytes is 3-4 h in the liver and 5-8 h in the hepatic LNs, in a normal steady state. Recirculating lymphocytes might transmigrate through the portal vein as well as the sinusoid in the periportal zone. This rapid transit might enable an efficient surveillance of the liver portal area by the recirculating lymphocytes.
Xu
Xue-Dong
XD
Department of Anatomy (Macro), and SORST, Dokkyo Medical University, Tochigi 321-0293, Japan.
Ueta
Hisashi
H
Zhou
Shu
S
Shi
Changde
C
Koga
Daisuke
D
Ushiki
Tatsuo
T
Matsuno
Kenjiro
K
D000818:Animals; D002465:Cell Movement / Q000276:immunology*; D005434:Flow Cytometry; D007150:Immunohistochemistry; D007700:Kinetics; D008099:Liver / Q000276:immunology*; D008196:Lymph / Q000166:cytology* / Q000276:immunology; D008197:Lymph Node Excision; D017710:Lymphocyte Transfusion; D008214:Lymphocytes / Q000276:immunology* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D051381:Rats; D018709:Statistics, Nonparametric; D013897:Thoracic Duct / Q000276:immunology*; D013997:Time Factors