Uptake of methylamine-activated alpha 2-macroglobulin by rat liver.
Serum clearance of alpha 2M-Me or alpha 2M-Tr is rapid and identical. Alpha 2M-Tr is almost exclusively taken up in the liver by the parenchymal cells; the uptake of alpha 2M-Me is equally shared between endothelial and parenchymal cells. Blocking the scavenger receptor on endothelial cells by polyinosinic acid reduces the uptake of alpha 2M-Me to 40% of the control value; under these conditions, alpha 2M-Me is only associated with the parenchymal cells. These results show the following: (1) activation of alpha 2M by methylamine or trypsin is different; (2) the scavenger receptor on endothelial cells functions as a system for the uptake of alpha 2M-Me in addition to the specific alpha 2M receptor on parenchymal cells.
Boers
W
W
Van Gool Laboratory of Experimental Internal Medicine, Academic Medical Center, Amsterdam, The Netherlands.
Linthorst
C
C
van Dijk
M C
MC
van Berkel
T J
TJ
D000818:Animals; D001692:Biological Transport; D008099:Liver / Q000378:metabolism*; D008297:Male; D008744:Methylamines / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D014018:Tissue Distribution; D014357:Trypsin / Q000378:metabolism; D000511:alpha-Macroglobulins / Q000378:metabolism*
D008744:Methylamines; D000511:alpha-Macroglobulins; C027451:methylamine; D014357:Trypsin