Title: Thrombocytic concentrations of diadenosintetraphosphate correlate to carotid intima-media-thickness in patients with essential hypertension
Abstract: An increased intima-media-thickness of large arteries is an early vascular wall alteration in patients with essential hypertension. Diadenosinpolyphosphates (APnAs) are endogeneous vasoactive substances. Data from our studies showed that thrombocytic concentrations of (APnAs) are increased in essential hypertension. Additionally, AP4A has been shown to stimulate proliferation of vascular smooth muscle cells. We investigated a possible relation between concentrations of diadenosinpolyphosphates and carotid intima-media-thickness in patients with essential hypertension. In 17 patients (age 46±3 years, BMI 26±1 kg/m) with mild, never treated essential hypertension thrombocytic concentrations of AP3A, AP4A, AP5A and AP6A were quantified by HPLC and related to content of β-thromboglobulin (β-T). By high-resolution ultrasound (8 MHz, Biosound 2000) three segments of the carotid artery were studied and the maximal intima-media-thickness (IMTmax) was measured. Results were as follows (MW±SEM): SBP/DBP 155±4 / 91±3 mmHg, IMTmax 1,05±0.05 mm, AP3A: 52±6, AP4A: 149±27, AP5A: 52±6, AP6A: 9±1 ng/μg β -T. A significant positive correlation was found between IMTmax of the carotid artery and thrombocytic concentrations of AP4A (r=0.48 p<0.05). Correlations to the other APnAs did not reach statistical significance. We found a significant relation between carotid intima-media-thickness and thrombocytic concentrations of AP4A in untreated patients with mild essential hypertension. We conclude therefore that increased thrombocytic concentrations of diadenosintetraphosphate may contribute to structural alterations of the carotid artery in hypertension.