Effect of aging on the expression of intracellular Ca(2+) transport proteins in a rat heart.
Aging process is accompanied by various biological dysfunctions including altered calcium homeostasis. Modified calcium handling might be responsible for changed cardiac function and potential development of the pathological state. In the present study we compared the mRNA and protein levels of the intracellular Ca(2+)-handling proteins--inositol 1,4,5-trisphosphate receptor (IP(3)R), ryanodine receptor (RyR), sarcoplasmic reticulum Ca(2+) pump (SERCA2), and also transient receptor potential C (TRPC) channels in cardiac tissues of 5-, 15-, and 26-month-old rats. Aging was accompanied by significant increase in the mRNA levels of IP(3)R and TRPC channels in both ventricles and atria, but mRNA level of the type 2 RyR was unchanged. Protein content of the IP(3)R1 correlated with mRNA levels, in the left ventricle of 15- and 26-month-old rats the value was approximately 1.8 and 2.8-times higher compared to 5-month-old rats. No significant differences were observed in mRNA and protein levels of the SERCA2 among 5-month-old and aged rats. However, Ca(2+)-ATPase activity significantly decreased with age, activities in 5-, 15-, and 26-month-old rats were 421.2 +/- 13.7, 335.5 +/- 18.1 and 304.6 +/- 14.8 nmol P(i) min(-1) mg(-1). These results suggest that altered transporting activity and/or gene expression of Ca(2+)-handling proteins of intracellular Ca(2+) stores might affect cardiac function during aging.
Kaplan
P
P
Department of Biochemistry, Jessenius Faculty of Medicine, Comenius University, Mala Hora 4, Martin, Slovak Republic.
Jurkovicova
D
D
Babusikova
E
E
Hudecova
S
S
Racay
P
P
Sirova
M
M
Lehotsky
J
J
Drgova
A
A
Dobrota
D
D
Krizanova
O
O
D000375:Aging / Q000502:physiology*; D000818:Animals; D001692:Biological Transport / Q000502:physiology; D002118:Calcium / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D006325:Heart Atria / Q000378:metabolism; D006352:Heart Ventricles / Q000378:metabolism; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000235:genetics / Q000378:metabolism; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011921:Rats, Inbred WKY; D019837:Ryanodine Receptor Calcium Release Channel / Q000235:genetics / Q000378:metabolism; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000235:genetics / Q000378:metabolism; D050051:Transient Receptor Potential Channels / Q000235:genetics / Q000378:metabolism
C506948:Atp2a2 protein, rat; D053496:Inositol 1,4,5-Trisphosphate Receptors; D020033:Protein Isoforms; D019837:Ryanodine Receptor Calcium Release Channel; D050051:Transient Receptor Potential Channels; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D002118:Calcium