Evaluation of organ glucose metabolism by 18F-FDG accumulation with insulin loading in aged mice compared with young normal mice

Abstract

It is important to determine the functional changes of organs that occur as a result of aging, the understanding of which may lead to the maintenance of a healthy life. Glucose metabolism in healthy bodies is one of the potential markers used to evaluate the changes of organ function. Thus, information about normal organ glucose metabolism may help to understand the functional changes of organs. [18F]-Fluoro-2-deoxy-2-d-glucose (18F-FDG), a glucose analog, has been used to measure glucose metabolism in various fields, such as basic medical research and drug discovery. However, glucose metabolism changes in aged animals have not yet been fully clarified. The aim of this study is to evaluate changes in glucose metabolism in organs and brain regions by measuring 18F-FDG accumulation and 18F-FDG autoradiography with insulin loading in aged and young wild-type mice. In the untreated groups, the levels of 18F-FDG accumulation in the blood, plasma, muscle, lungs, spleen, pancreas, testes, stomach, small intestine, kidneys, liver, brain, and brain regions, namely, the cortex, striatum, thalamus, and hippocampus, were all significantly higher in the aged mice. The treated group showed lower 18F-FDG accumulation levels in the pancreas and kidneys, as well as in the cortex, striatum, thalamus, and hippocampus in the aged mice than the untreated groups, whereas higher 18F-FDG accumulation levels were observed in those in the young mice. These results demonstrate that insulin loading decreases effect on 18F-FDG accumulation levels in some organs of the aged mice. Therefore, aging can increase insulin resistance and lead to systemic glucose metabolism dysfunction.

A combination of the geroprotectors trametinib and rapamycin is more effective than either drug alone

“…We therefore used the 18F-FDG PET/CT longitudinal data to address whether trametinib and combined drug treatment could attenuate the age-related increase in glucose uptake (Fig 4A -G). As expected, 18F-FDG uptake increased with age in control females across the whole brain (Fig 4A , E), consistent with a previous study [32]. There was a significant increase in 18F-FDG uptake between 12 and 24 months in the striatum and cerebellum, but not the cortex (Fig 4A , E).…”

“…Glucose uptake in the brain increases during ageing in mice [32] and may be linked to impaired cognitive function [33]). We therefore used the 18F-FDG PET/CT longitudinal data to address whether trametinib and combined drug treatment could attenuate the age-related increase in glucose uptake (Fig 4A -G).…”

Organ-Specific Fuel Rewiring in Acute and Chronic Hypoxia Redistributes Glucose and Fatty Acid Metabolism

“…We conducted FDG PET scans in mice housed at 21% and 8% F i O 2 for 3 hours, 24 hours, 1 week, and 3 weeks. We also extracted organs and used a gamma counter to quantify the 18 F signal from each organ (Zhao et al, 2021).…”