Tag Archives: iNOS
Circulating levels of potential markers of ischemic stroke in patients with the different forms of atrial fibrillation and chronic heart failure
A. O. Tykhomyrov1*, O. Yu. Sirenko2, O. V. Kuryata2
1Department of Enzyme Chemistry and Biochemistry,
Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv, Ukraine;
2Department of Internal Medicine 2, Phthisiology,
Occupational Diseases and Clinical Immunology, Dnipro State Medical University, Dnipro, Ukraine;
*e-mail: artem_tykhomyrov@ukr.net
Received: 19 January 2024; Revised: 13 March 2024;
Accepted: 17 March 2024; Available on-line: 30 April 2024
Atrial fibrillation (AF) is the most common abnormal type of heart rhythm (cardiac arrhythmia), which is considered the leading cause of stroke. There have been limited studies on the prognostic markers for atrial disease and AF-associated ischemic stroke, despite the high demand for this procedure in daily clinical practice to monitor disease course and assess risk of stroke in patients with AF and chronic heart failure (CHF). Thus, the aim of the present study was to evaluate the levels of serum biomarkers related to ischemic stroke in CHF patients with the different forms of AF. Forty-six patients with various types of AF (paroxysmal, persistent and permanent) with or without ischemic stroke were enrolled in the study, 36 clinically healthy donors served as a control. The levels of inducible nitric oxide synthase (iNOS), vascular endothelial growth factor (VEGF) and angiostatins (AS) were evaluated by western blot analysis in the serum. The levels of active matrix metalloproteinases (MMPs) were analysed by gelatin zymography. Elevated levels of iNOS were shown in patients with all AF forms as compared with control, but iNOS levels in post-ischemic patients were significantly higher than that in paroxysmal AF individuals. However, the levels of VEGF and AS did not differ from the baseline value in patients with paroxysmal AF, while dramatic increase of their contents was shown in post-stroke patients with persistent and permanent types of AF. Elevated active MMP-9 levels were shown to be associated with the diagnosis of all AF forms, regardless of the occurrence of stroke. Taken together, our findings demonstrate that tested proteins can be considered as valuable biomarkers of AF forms transformation and potentially useful for ischemic stroke risk stratification in patients with AF and CHF. Observed changes in regulatory protein levels may expand our understanding of pathological roles of endothelial function dysregulation, disrupted angiogenesis balance and abnormal tissue remodeling in AF and associated ischemic events.
Indexes of nitric oxide system in experimental antiphospholipid syndrome
O. Z. Yaremchuk, K. A. Posokhova, І. P. Kuzmak,
M. I. Kulitska, I. М. Klishch, M. M. Korda
I. Horbachevsky Ternopil National Medical University, Ukraine;
e-mail: yaremchuk@tdmu.edu.ua
Received: 11 November 2019; Accepted: 21 January 2020
Antiphospholipid syndrome (APS) is an autoimmune disease characterized by the presence of antibodies to negatively charged membrane phospholipids (aPL). Endothelial dysfunction is one of the most dangerous APS manifestations followed by thrombosis, placental insufficiency and often foetal death due to circulatory disorders in placenta blood vessels. It is established that synthesis and bioavailability of nitric oxide (NO) in the endothelium are impaired at APS, but the role of NO system in pregnancy failure at this pathology remains ambiguous. The aim of this research was to estimate the indexes of the nitric oxide system in animals with an experimental antiphospholipid syndrome before pregnancy and on the 18th day of pregnancy, without treatment and under treatment with nitric oxide synthesis modulators (L-arginine and aminoguanidine). In the blood serum and liver of the BALB/c mice with experimental APS, the content of eNOS and iNOS– by ELISA and the level of NO2– and NO3– with the use of Gris reagent were determined before pregnancy and on the 18th day of pregnancy. The data obtained indicate the relative inefficient NO production by eNOS and NO hyperproduction by iNOS in the blood serum and liver of mice in the pathogenesis of experimental APS. Thus, in mice with APS before pregnancy and on the 18th day of the pregnancy, the eNOS content and NO2– level were decreased while the iNOS content and NO3– level were increased compared to the indexes in the control animal group. L-arginine administration to the animals with APS at the follow-up periods resulted in an increased eNOS content and NO2–, NO3– levels in blood serum and liver with the simultaneous decrease in iNOS content in the liver as compared to indexes in untreated mice with APS. The combined use of L-arginine and selective iNOS inhibitor aminoguanidine caused a significant increase in eNOS content and a decrease in iNOS content followed by normalization of NO2– and NO3– levels in blood and liver of mice with experimental APS before pregnancy and on the 18th day of pregnancy compared to untreated mice with APS.