1. Total plasma concentrations of bromine, copper, rubidium, selenium and zinc were measured in spontaneously hypertensive rats (SHR) and Wistar–Kyoto rats (WKY) of 5–20 weeks of age, using an X-ray fluorescence spectrometry technique.
2. Although plasma levels of bromine, rubidium, selenium and zinc varied at different ages when comparing SHR and WKY, their general evolution was similar. Copper levels increased more in SHR than in WKY.
3. These perturbations in trace element levels could perhaps participate in the establishment of hypertension in SHR, but could also be due to genetic differences between the strains, unrelated to the development of hypertension.