Transferrin glycosylation in hypoxia.
The aim of this study was to examine the effect of reduced O2 tension on the glycosylation of transferrin. Rats were placed in a hypobaric chamber (380 mmHg) that corresponded to an altitude of 5486 m above sea level for 21 days. The animals responded with marked increases in hematocrit (from 44 to 76%) and cardiac weight, and with reductions in the concentration of plasma transferrin averaging 15%. Analyses of their plasma transferrin by serial anion-exchange and lectin affinity chromatography revealed no changes in the extent of glycan branching. However, there was a moderate rise in the proportion of fucosylated transferrin molecules (fucosylation index) and a slight decrease in the transferrin fraction bearing a tetrasialylated biantennary glycan. The fucosylation index correlated positively with plasma transferrin concentrations in the test animals, but not in the controls. In contradistinction to the situation with transferrin, hypoxic rats exhibited a reduced fucosylation index of immunoglobulin G.
Regoeczi
E
E
Department of Pathology, McMaster University Health Sciences Centre, Hamilton, Ont., Canada.
Kay
J M
JM
Chindemi
P A
PA
Zaimi
O
O
Suyama
K L
KL
D000818:Animals; D002846:Chromatography, Affinity; D002848:Chromatography, DEAE-Cellulose; D005260:Female; D005643:Fucose / Q000378:metabolism; D006031:Glycosylation; D006321:Heart; D006400:Hematocrit; D000860:Hypoxia / Q000378:metabolism*; D007930:Leucine / Q000378:metabolism; D009929:Organ Size; D011134:Polysaccharides / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D014168:Transferrin / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*
D011134:Polysaccharides; D014168:Transferrin; D005643:Fucose; D007930:Leucine