67Ga as a biosensor of iron needs in different organs: Study performed on male and female rats subjected to iron deficiency and exercise

The aim of the present study was to determine the iron needs in different organs and tissues using 67Ga as a biosensor in males and females rats subjected to iron deficiency (ID) and voluntary exercise (EX). 67Ga citrate was injected i.p. to female and male Wistar rats (n = 5/sex/group). Groups: Control (sedentary conditions), Control + EX, ID and ID + EX. To determine the 67Ga uptake, samples from the following regions of interest (ROIs) were extracted 12 h post-injection: blood, liver, gonads, bone marrow, heart, adrenal glands, skeletal muscle, stomach, kidney, eyeball, sciatic nerve, small intestine and peritoneum. The total 67Ga uptake was 412% higher in ID subjects than in control subjects, being 1011% higher in ID-males than ID-females. In ID-females, the ROIs with the greater 67Ga uptake were blood, kidney and bone marrow, while in ID-males they were sciatic nerve, eyeball and adrenals, which demonstrates that the biodistribution differed between sexes in sedentary conditions but when subjected to EX, the biodistribution was similar in each sex group although females had a greater 67Ga uptake. In ID + EX subjects, the ROIs that showed the highest uptake were sciatic nerve, eyeball and adrenal glands. Using 67Ga as a biosensor, it is possible to identify the needs of iron that each organ requires to perform their functions in normal physiological conditions. In addition, a higher or lower 67Ga uptake in a specific organ may indicate its malfunction or show damage.