The aim of this study was to compare the vascular reactivity and morphology of iliac artery (IA) in adult spontaneously hypertensive rats (SHR) and hereditary hypertriglyceridemic (hHTG) rats. The isolated rings of iliac artery (IA) from Wistar rats (controls), SHR and hHTG rats were used for measurement of relaxant responses to acetylcholine (ACh) and contractile responses to noradrenaline (NA). Morphological changes of IA were measured using light microscopy. Systolic blood pressure (BP) measured by plethysmographic method was increased in SHR approximately by 88 % and in hHTG rats by 44 % compared to controls. BP increase was accompanied by cardiac hypertrophy. In both SHR and hHTG groups (experimental groups) reduced relaxation to ACh and enhanced maximal contraction and sensitivity to adrenergic stimuli were observed. The sensitivity to NA in SHR was higher also in comparison with hHTG. Geometry
of IA in both experimental groups revealed increased wall thickness and wall cross-sectional area, in SHR even in comparison with hHTG. Inner diameter was decreased in both experimental groups. Thus, independently of etiology, hypertension in both models was connected with impaired endothelial function accompanied by structural alterations of
IA. A degree of BP elevation was associated with arterial wall hypertrophy and increased contractile sensitivity.
High blood pressure, increased level of cholesterol, diabetes, hypertriglyceridemia and obesity are risk factors accompanied metabolic syndrome. The aim of the study was to compare geometry of carotid artery (AC) of 3-week-old (3w) and 52-week-old (52w) hereditary hypertriglyceridemic rats (hHTG) and spontaneously hypertensive rats (SHR) which represent a genetic model of human essential hypertension with age-matched Wistar rats. After sacrificing the rats were perfused with a glutaraldehyde fixative under the pressure 90 mm Hg (3w) and 120 mm Hg (52w) for 10 min via cannula placed into left ventricle. Middle part of AC was excised and processed according to standard electron
microscopy procedure. Geometry of AC was evaluated in light microscopy. SHR vs. Wistar rats: BP of 3w did not differ, in 52w it was increased; cardiac hypertrophy was found in both ages; wall thickness (WT) and cross sectional area (CSA) in 3w did not differ, in 52w both were increased; inner diameter (ID) in 3w and 52w was decreased; WT/ID was increased in both ages. Hereditary HTG vs. Wistar rats: BP was increased in both periods; cardiac hypertrophy was observed in 3w; WT in 3w was decreased, in 52w it was increased; CSA and ID were decreased in both ages; WT/ID was increased only in 52w. Discrepancies between development of BP, cardiac hypertrophy in SHR and hHTG rats were observed. Alterations of BP were not in harmony with alterations in geometry of carotid arteries in both SHR and hHTG rats. We suggest that BP is not the main stimuli evoked hemodynamic and structural alterations of cardiovascular system in ontogenic development of SHR and hHTG rats.