TY - JOUR
T1 - Developmental changes in the amount and functional state of UDP-glucuronosyltransferase
AU - Dannenberg, Andrew J.
AU - Worman, Howard J.
AU - Scarlata, Suzanne
N1 - Funding Information:
This work was supportedb y grants from the NIH (IK08 DKI992. KIIDK01790, GM3t)9241 and NSF (DMB8504014)A. .D. is the recipiento f the Dr. Mark WeiusteinL iver Scholar Award. The authorst hankDr. Thomas Donnclly lot his assistancein preparingt he anti-UDP-glucuronus3'ltransferaanstei serumW. e also thank Mr. Murray Cohen for his assistancei n the course of this research.
PY - 1992/6/12
Y1 - 1992/6/12
N2 - The effect of postnatal development on the activity of liver microsomal UDP-glucuronosyltransferase was determined in male Wistar rats between 25 and 200 days of age using p-nitrophenol as aglycone. Enzyme activity (measured at 1.0 mM UDP-glucuronic acid, 0.05 mM p-nitrophenol) decreased 55% between 25 and 88 days of age and was constant thereafter. Treatment of microsomes with palmitoyl-lysophosphatidylcholine, which allows for an estimation of the amount of enzyme, showed approximately a four-fold decrease in enzyme concentration during the same period. This decrease was confirmed by Western blotting of microsomes with anti-UDP-glucuronosyltransferase antiserum. The fact that a nearly four-fold decline in enzyme concentration led to only a 55 decrease in activity indicates that there was an increase in activity per molecule of UDP-glucuronosyltransferase as the concentration of enzyme decreased. Treatment of microsomes with high pressure or detergent caused a greater extent of enzyme activation in microsomes prepared from 25 than 200 day old rats, suggesting that a fraction of the enzyme in older rats was activated in untreated microsomes. Fatty acid analysis of liver microsomal lipids during postnatal development revealed changes in docosahexaenoic acid (22:6) which correlated with levels of UDP-glucuronosyltransferase activity.
AB - The effect of postnatal development on the activity of liver microsomal UDP-glucuronosyltransferase was determined in male Wistar rats between 25 and 200 days of age using p-nitrophenol as aglycone. Enzyme activity (measured at 1.0 mM UDP-glucuronic acid, 0.05 mM p-nitrophenol) decreased 55% between 25 and 88 days of age and was constant thereafter. Treatment of microsomes with palmitoyl-lysophosphatidylcholine, which allows for an estimation of the amount of enzyme, showed approximately a four-fold decrease in enzyme concentration during the same period. This decrease was confirmed by Western blotting of microsomes with anti-UDP-glucuronosyltransferase antiserum. The fact that a nearly four-fold decline in enzyme concentration led to only a 55 decrease in activity indicates that there was an increase in activity per molecule of UDP-glucuronosyltransferase as the concentration of enzyme decreased. Treatment of microsomes with high pressure or detergent caused a greater extent of enzyme activation in microsomes prepared from 25 than 200 day old rats, suggesting that a fraction of the enzyme in older rats was activated in untreated microsomes. Fatty acid analysis of liver microsomal lipids during postnatal development revealed changes in docosahexaenoic acid (22:6) which correlated with levels of UDP-glucuronosyltransferase activity.
KW - (Rat)
KW - Development
KW - Liver
KW - UDP-glucuronosyltransferase
UR - http://www.scopus.com/inward/record.url?scp=0026651793&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0026651793&partnerID=8YFLogxK
U2 - 10.1016/0304-4165(92)90036-T
DO - 10.1016/0304-4165(92)90036-T
M3 - Article
C2 - 1610880
AN - SCOPUS:0026651793
VL - 1116
SP - 250
EP - 255
JO - Biochimica et Biophysica Acta - General Subjects
JF - Biochimica et Biophysica Acta - General Subjects
SN - 0304-4165
IS - 3
ER -