Electrolytic analysis carried out with the atomic absorption spectrophotometer permitted to compare the cationic (Ca2+, Mg2+, Zn2+, K+ and Na+) tissue content of spontaneously hypertensive male rats (SHR) and normotensive male Wistar rats (NWR). In all SHR-tissues, Zn2+ is augmented, but mainly in the atria (left atrium), inferior vena cava, left ventricle, and skeletal muscle. The inferior cava vein and the right atrium have a similar, accentuated high bivalent (Ca2+, Mg2+, and Zn2+) cation content; Ca2+ and Mg2+ is present in a minor content in the right ventricle and type II "pale" skeletal muscle while only Mg2+ was also reduced in the left atrium, aorta, and the whole blood. A higher K+ concentration is seen in the right atrium, aorta, and type I "red" skeletal muscle. In the aortic wall and the whole blood a higher Na+- tissue content is found, confirming earlier observations. There is a discret water retention in the tissues from the left ventricle and skeletal muscle, simultaneously with a small depletion in the whole blood. We have concluded, that there is a specific cationic profile in SHR structural and functional different cardiovascular tissues, including skeletal muscle. The cationic tissue distribution is related to underlying genetic and adaptative factors and may be involved into specific drug effects.