Influence of the zoledronic acid accumulative effect on the microcirculation state in the rat periodontium

Abstract

Objective. To determine the character of changes in the reactivity of rat periodontal microvessels depending on the multiplicity of zoledronic acid administration. Material and Methods. Wistar rats (n = 36) were divided into groups of 9 rats each. In group No. 1 (control), rats were injected with 0.9% sterile sodium chloride solution once a week for 3 weeks; in group No. 2, rats were injected once with zoledronic acid (ZA) once a week; in group No. 3, rats were injected intravenously with ZA once a week for 3 weeks; in group No. 4, rats were injected with ZA once a week for 6 weeks. ZA was administered at a dose of 0.18 mg/kg in 0.9% sterile sodium chloride solution in the volume of 1 ml/kg. The microcirculation parameters in the periodontium were determined before ZA administration and on the 3rd day after administration by laser Doppler flowmetry (LDF) and ultrasound high-frequency dopplerography (UHFD) methods. Periodontal vascular reactivity was determined using acetylcholine assay. Results. After ZA administration, the indices of microcirculatory vascular reactivity decreased in rats of groups No. 3 and No. 4 in comparison with the results obtained before ZA administration: at ultrasound examination the maximum increase of blood flow velocity was noted at the 2nd minute and amounted to 133±8,5, 112±7,8 %, respectively. In rats of group No. 2, the increase in blood flow velocity corresponded to the value of the control group. In LDF study, the maximal blood flow rates were lower than in the control group in rats administered the drug for 3 and 6 weeks, respectively. Conclusion. Zoledronic acid dose-dependently causes impaired vascular responsiveness and leads to a decrease in endothelium-dependent vasodilation.