Age‐associated change in pyruvate metabolism investigated with hyperpolarized 13C‐MRI of the human brain

Abstract

AbstractIn this study, hyperpolarized 13C MRI (HP‐13C MRI) was used to investigate changes in the uptake and metabolism of pyruvate with age. Hyperpolarized 13C‐pyruvate was administered to healthy aging individuals (N = 35, ages 21–77) and whole‐brain spatial distributions of 13C‐lactate and 13C‐bicarbonate production were measured. Linear mixed‐effects regressions were performed to compute the regional percentage change per decade, showing a significant reduction in both normalized 13C‐lactate and normalized 13C‐bicarbonate production with age: per decade for 13C‐lactate and per decade for 13C‐bicarbonate. Certain regions, such as the right medial precentral gyrus, showed greater rates of change while the left caudate nucleus had a flat 13C‐lactate versus age and a slightly increasing 13C‐bicarbonate versus age. The results show that both the production of lactate (visible as 13C‐lactate signal) as well as the consumption of monocarboxylates to make acetyl‐CoA (visible as 13C‐bicarbonate signal) decrease with age and that the rate of change varies by brain region.