Cytochrome c mRNA levels decrease in senescent rat heart.
The concentration of mitochondria decreases in the heart as rodents age from maturity to senescence. The reason for this change is not known. One purpose of the present study was to determine if cytochrome c mRNA, representative of proteins of the inner mitochondrial membrane, decreased in the hearts of Fischer 344 rats as they aged from 12 to 24 months. Twenty-two percent less cytochrome c mRNA existed per given quantity of extracted RNA from the heart in 24-month-old rats as compared with the 12-month-old group. No change in the quantities of cardiac alpha-actin mRNA, Ca2+/calmodulin protein kinase II mRNA or 18S rRNA was noted between 12- and 24-month-old hearts. Thus, the decrease in cytochrome c mRNA suggests that decreases in mRNAs for proteins of the inner mitochondrial membrane could play some role in the diminished concentration of mitochondria that exists in the senescent heart.
Biggs
R B
RB
Department of Physiology and Cell Biology, University of Texas Medical School, Houston 77225.
Hanley
R M
RM
Morrison
P R
PR
Booth
F W
FW
D000199:Actins / Q000378:metabolism; D000375:Aging / Q000378:metabolism*; D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D003574:Cytochrome c Group / Q000378:metabolism*; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D011494:Protein Kinases / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D012337:RNA, Ribosomal, 18S / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344
D000199:Actins; D003574:Cytochrome c Group; D012333:RNA, Messenger; D012337:RNA, Ribosomal, 18S; D011494:Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases