The effect of aging and dietary restriction on the retinoylation of nuclear matrix proteins in rats.
The labeling in vivo of young ad libitum (Y/AL) and old diet restricted (O/DR) rats with [3H]retinoic acid (RA) for 6 hours, and the exposure of electrophoretically separated nuclear matrix proteins from bone marrow tissue on film for 48 days revealed the presence of eleven retinoylated proteins. Dosing with RA (100 mg/kg body weight) for 96 hours and exposure to [3H]RA enhanced the levels of radioactive incorporation of several nuclear matrix proteins, including p51, and p55, similarly in Y/AL and O/DR rats. Dosing of old ad libitum (O/AL) rats with [3H]RA for 6 hours showed the incorporation of six proteins following 48 days of exposure on film. Long-term dosing of RA (96 hours) did not increase [3H]RA incorporation in these proteins, including p51 and p55, in O/AL rats. Increasing the level of RA by two-fold (200 mg/kg body weight) in Y/AL and O/DR rats elicited an increase in the incorporation levels of [3H]RA in five proteins. This dose response following increased levels of RA was not seen in the retinoylated proteins of O/AL animals. Analysis by the Western blotting technique showed p51 and p55 from rat bone marrow cells to have the same immunochemical determinates with proteins of identical molecular masses in HL60 cells. The levels of retinoylation of nuclear matrix proteins in O/DR animals, altered by age- and diet-dependent factors, suggests a condition that is more reminiscent of Y/AL than of O/AL animals.
Division of Genetic Toxicology, National Center for Toxicological Research, AR 72079-9502, USA.
J L
JL
Pipkin
W
W
Hinson
L E
LE
Lyn-Cook
P H
PH
Duffy
R J
RJ
Feuers
J E
JE
Leakey
K B
KB
Aly
R W
RW
Hart
D A
DA
Casciano
D000375:Aging / Q000378:metabolism*; D000818:Animals; D034961:Antigens, Nuclear; D001853:Bone Marrow / Q000378:metabolism; D004032:Diet; D015180:Electrophoresis, Gel, Two-Dimensional; D005508:Food Deprivation; D018922:HL-60 Cells; D006801:Humans; D007120:Immunochemistry; D007930:Leucine / Q000378:metabolism; D008297:Male; D008970:Molecular Weight; D009687:Nuclear Proteins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D051381:Rats; D011916:Rats, Inbred F344; D018168:Receptors, Retinoic Acid / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D014212:Tretinoin / Q000378:metabolism* / Q000494:pharmacology
D034961:Antigens, Nuclear; D009687:Nuclear Proteins; D018168:Receptors, Retinoic Acid; D014212:Tretinoin; D007930:Leucine