Aging effects on hepatic NADPH cytochrome P450 reductase, CYP2B1&2, and polymeric immunoglobulin receptor mRNAs in male Fischer 344 rats.
Aging perturbs the expression of many liver proteins, but the mechanisms remain unresolved. Expression of hepatic NADPH cytochrome P450 reductase, phenobarbital-induced CYP2B1&2, and the polymeric immunoglobulin receptor (pIgR) decline as a function of aging. We examined the effect of aging on the expression of the mRNA transcripts of these proteins, as well as those of alpha 2u-globulin and beta-actin in male F344 rats. Despite age-related losses in the expression of P450 reductase and plasma membrane-bound pIgR in the rat liver (approximately 30-50%), aging is is accompanied by 1) no change and 2) a modest decline (< 20%) in their respective mRNA steady state levels. On the other hand, the expression of phenobarbital-induced microsomal CYP2B1&2 and the steady state level of its mRNA exhibit parallel age-dependent shifts. The mRNA transcript for alpha 2u-globulin declines between maturity and old age, whereas the beta-actin mRNA level remains unchanged. These preliminary data are consistent with previous studies which suggest that aging may perturb hepatic CYP2B1&2 and alpha 2u-globulin at the transcriptional level, whereas changes in the expression of P450 reductase and pIgR may reflect posttranscriptional modifications.
van Bezooijen
R L
RL
Cell Biology & Aging Section, Department of Veterans Affairs Medical Center, San Francisco, California 94121.
Wang
R K
RK
Lechner
M C
MC
Schmucker
D L
DL
D000199:Actins / Q000235:genetics / Q000378:metabolism; D000375:Aging / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D000510:Alpha-Globulins / Q000235:genetics / Q000378:metabolism; D000818:Animals; D019362:Cytochrome P-450 CYP2B1; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism; D008099:Liver / Q000276:immunology / Q000378:metabolism*; D008297:Male; D009251:NADPH-Ferrihemoprotein Reductase / Q000235:genetics / Q000378:metabolism; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D011916:Rats, Inbred F344; D011971:Receptors, Immunologic; D012635:Secretory Component / Q000235:genetics / Q000378:metabolism
D000199:Actins; D000510:Alpha-Globulins; D012333:RNA, Messenger; D011971:Receptors, Immunologic; D012635:Secretory Component; C013803:alpha 2u globulin; D003577:Cytochrome P-450 Enzyme System; D010088:Oxidoreductases; D019362:Cytochrome P-450 CYP2B1; D009251:NADPH-Ferrihemoprotein Reductase