Dietary magnesium intake can affect mechanical properties of rat carotid artery

The purpose of the present study was to determine the effects of Mg deficie ncy and supplementation on the mechanical properties of the rat common caro tid artery. The internal diameter and intra-arterial pressure of carotid ar tery were measured continuously using an echo-tracking device. Systolic, di astolic and mean intra-arterial pressures were not significantly different in Mg-deficient, -supplemented or control rats. Histological examination sh owed a larger cross-sectional area, increased intima-media thickness and a greater media:lumen value in carotid artery of Mg-deficient rats, indicatin g that Mg deficiency may directly stimulate growth and/or proliferation of arterial wall components. In addition, we observed a negative linear relati onship between intima-media thickness and plasma Mg concentration, suggesti ng that increased Mg intake may counteract arterial wall hypertrophy. Neith er Mg deficiency nor supplementation modified the arterial distensibility v . intra-arterial pressure curve or the E-inc v. wall stress curve, indicati ng that dietary Mg intake did not modify wall stiffness in young rats. At m ean intra-arterial pressure, the stress and E-inc values were, however, sig nificantly lower in Mg-deficient rats (P<0.05 in both cases); this finding could be related to the alteration in the geometry of the carotid artery. I n conclusion, these findings suggest that Mg deficiency modifies the mechan ical properties of the common carotid artery in young rats. Since Mg defici ency is considered a risk factor, these mechanical alterations could contri bute to the development of atherosclerosis, hypertension and cardiovascular diseases.