Heart alterations in spontaneously hypertensive rats: immunochemical and immunohistochemical assessment of the activity of dextrorotatory form of thioctic acid.

Hypertension represents a risk factor for cardiovascular diseases [1]. Increasing evidence attributed the main role of oxidative stress in cardiovascular damage, promoting endothelial dysfunction, vascular remodeling, and inflammation. Excess bioavailability of reactive oxygen species (ROS), often is accompanied by structural mitochondria abnormalities in the cardiomy-ocyte [2,3]. The most effective treatment in the management of hypertension seems to be the administration of anti-hypertensive drugs with antioxidant properties [4].Thioctic acid (TIO) is an antioxidant existing in nature and expressed in two optical iso-mers. The dextrorotatory form is the naturally occurring eutomer, whereas the most used for-mulation of the compound in clinical practice is the mixture of (+) and (-) enantiomers. Previ-ously, we demonstrated that TIO-(+) is one of the more appropriate antioxidant molecules to prevent cardiac and renal alterations associated with hypertension [5].The present study was designed to investigate the effect of 4 weeks of treatment with TIO-(+) on the heart of spontaneously hypertensive rats (SHR), using immunochemical and immunohisto-chemical techniques. 125 mmol/Kg/day of TIO-(+) was administered intraperitoneally in 24-weeks-old SHR. Hypertensive rats were compared to age-matched normotensive Wistar Kyoto (WKY) rats.Blood pressure values were significantly decreased in treated SHR compared to the control one. This is probably related to the effects at the levels of the endothelial vessels that determine vasodilation. Left ventricular cardiomyocytes’ hypertrophy deposition of reticulin, collagen fib-ers, proteins, and nucleic acid oxidation accompanied by an increased expression of interleu-kins, such as IL-1 beta, IL-6 and tumor necrosis factor-alpha were found in SHR. These altera-tions were reduced in TIO-(+) treated animals. The effects observed after treatment with TIO-(+) nominate this molecule as one of the more appropriate antioxidants to prevent heart injury associated with hypertension, opening the opportunity to further evaluations in clinical trials.