ISSN:
1573-4919
Keywords:
6-phosphofructo-1-kinase
;
aging
;
heart
;
energy metabolism
;
metabolic regulation
;
isozymes
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
Abstract Relative to 2–3 month rats, total 6-phosphofructo-1-kinase (PFK) activity in heart atria from 12 month rats declined 31%; but, by 24 months it was decreased by only 13%. PFK activities from 12 and 24 month ventricles relative to the 2–3 month rat were decreased by 40% and 30%, respectively. This change in PFK activity in each heart region was associated with alterations of subunit composition. In heart atria from 12 and 24 month rats when compared to 3 month rats, the levels of L-type subunit were not significantly different; but the levels of the M-type subunit were decreased by 43% and 38%, respectively. With respect to levels in 2–3 month atria, the C-type subunit in 12 month atria decreased by 27%; and at 24 months it increased by 31%. Making the same comparison for the heart ventricle at 12 and 24 months, L-type subunit decreased by 30% and 24% respectively; M-type subunit decreased by approximately 47%; and the C-type subunit increased 1.9 and 4.7 fold, respectively. These age-related changes of subunit composition in atrial and ventricular PFK isozyme pools led to changes in their kinetic and regulatory properties suggesting that the aged rat could exhibit a diminished capacity to produce ATP from glucose.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02424574
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