Regulation of urea synthesis in sublobular regions of the liver lobule by oxygen.
Periportal and pericentral regions of the liver lobule were isolated from perfused rat liver using a micropunch and incubated in Krebs-Henseleit buffer (pH 7.6) containing 2% poly(ethylene glycol) in Eagle's basal medium, PMSF (50 micrograms/ml) and leupeptin (20 micrograms/ml) for 2 h at 25 degrees C under and O2/CO2 (95:5%) gas phase. Maximal rates of urea production from ammonium chloride were 96.4 +/- 8.7 and 32.8 +/- 5.4 mumol/g per h at 800 and 200 microM O2. Thus, urea synthesis was 2-3-times greater at high than low O2 tension in plugs from periportal and pericentral regions of the liver lobule.
Takei
Y
Y
Department of Pharmacology, UNC-CH 27599-7365.
Kauffman
F C
FC
Misra
U K
UK
Yamanaka
H
H
Thurman
R G
RG
D000818:Animals; D002245:Carbon Dioxide / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D051381:Rats; D014508:Urea / Q000378:metabolism*
D002245:Carbon Dioxide; D014508:Urea; D010100:Oxygen