Effect of GLP-1 Receptor Agonist on Ischemia Reperfusion Injury in Rats with Metabolic Syndrome.

Metabolic syndrome (MetS) represents an important factor that increases the risk of myocardial infarction, and more severe complications. Glucagon Like Peptide-1 Receptor Agonists (GLP-1RAs) exhibit cardioprotective potential, but their efficacy in MetS-related myocardial dysfunction has not been fully explored. Therefore, we aimed to assess the effects of exenatide and dulaglutide on heart function and redox balance in MetS-induced rats. Twenty-four Wistar albino rats with induced MetS were divided into three groups: MetS, exenatide-treated (5 µg/kg), dulaglutide-treated (0.6 mg/kg). After 6 weeks of treatment, in vivo heart function was assessed via echocardiography, while ex vivo function was evaluated using a Langendorff apparatus to simulate ischemia-reperfusion injury. Heart tissue samples were analyzed histologically, and oxidative stress biomarkers were measured spectrophotometrically from the coronary venous effluent. Both exenatide and dulaglutide significantly improved the ejection fraction by 3% and 7%, respectively, compared to the MetS group. Histological analyses corroborated these findings, revealing a reduction in the cross-sectional area of cardiomyocytes by 11% in the exenatide and 18% in the dulaglutide group, indicating reduced myocardial damage in GLP-1RA-treated rats. Our findings suggest strong cardioprotective potential of GLP-1RAs in MetS, with dulaglutide showing a slight advantage. Thus, both exenatide and dulaglutide are potentially promising targets for cardioprotection and reducing mortality in MetS patients.

Predictors of Non-Adherence to Medications in Hypertensive Patients.

Background: Elevated blood pressure (BP) is one of the leading causes for developing major cardiovascular events and still represents a major public health challenge worldwide. We aimed to provide data on predictors of poor adherence to medication in hypertensive patients in Serbia. Methods: Observational, analytical study was undertaken at a group of 388 patients who refilled their medications in the Pharmacy Institution, "Apoteka Kragujevac", Kragujevac, Serbia between Jan and Mar 2019. Afterward, we conducted a case-control study to evaluate the influence of the variables associated with the adherence. We used a self-developed questionnaire and SF-36 to assess the influence of the quality of life on medication adherence. Results: Results revealed four independent predictors of non-adherence: increased number of medications, living in a city, forgetfulness of the dosing regimen and low energy. The odds of non-adherence were the highest among the participants living in the city and the low energy was the only factor inversely associated with the level of non-adherence. Conclusion: Many factors were associated with the non-adherence to medication. Further studies are needed to find the most appropriate protocol to promote adherence. The four risk factors (increased number of medications, living in a city, forgetfulness of the dosing regimen and low energy) are associated with non-adherence in adult hypertensive patients.

The Effects of Thiamine Hydrochloride on Cardiac Function, Redox Status and Morphometric Alterations in Doxorubicin-Treated Rats.

Previous studies have suggested that thiamine has antioxidant activity and could decrease the production of ROS in various disorders. Our study focused on the effect of thiamine hydrochloride in the reversal of DOX-induced cardiotoxicity and compared it with the reversal in the absence of thiamine pre-treatment. Rats were divided into groups as follows: (a) thiamine + doxorubicin (TIA + DOX), (b) doxorubicin (DOX) and c) healthy (CTRL) groups. For 7 days, thiamine hydrochloride was administered at a dose of 25 mg/kg per day intraperitoneally, while a single dose of 15 mg/kg doxorubicin was injected into all groups except the CTRL group. We measured the following parameters: maximum rate of left ventricular development (dp/dt max), minimum rate of left ventricular development (dp/dt min), systolic left ventricular development (SLVP), diastolic left ventricular development (DLVP), heart rate (HR) and coronary flow (CF), pro-oxidative and antioxidative markers, cardiac activity, and histopathological evaluation. In our study, cardiac contractility was significantly altered after DOX treatment and diminished by thiamine pre-treatment. Additionally, pro-oxidant parameters were significantly increased in the DOX group. The levels of O2-, H2O2 and TBARS were significantly increased in the DOX group and decreased in the DOX + T group compared to those in the DOX group. Morphometric analyses showed moderately expressed interstitial fibrosis and degenerately modified cardiac muscle fibres, with signs of interfibrillary congestion, vacuolar degeneration and myocytolysis in the DOX group as visualized by H&E and Masson's Trichrome staining. Pre-treatment of thiamine hydrochloride before doxorubicin administration could decrease oxidative stress production, increase myocardial contractility and enhance the antioxidant defence system.

Protective Effects of Galium verum L. Extract against Cardiac Ischemia/Reperfusion Injury in Spontaneously Hypertensive Rats.

Galium verum L. (G. verum, lady's bedstraw) is a perennial herbaceous plant, belonging to the Rubiaceae family. It has been widely used throughout history due to multiple therapeutic properties. However, the effects of this plant species on functional recovery of the heart after ischemia have still not been fully clarified. Therefore, the aim of our study was to examine the effects of methanol extract of G. verum on myocardial ischemia/reperfusion (I/R) injury in spontaneously hypertensive rats (SHR), with a special emphasis on the role of oxidative stress. Rats involved in the research were divided randomly into two groups: control (spontaneously hypertensive rats (SHR)) and G. verum group, including SHR rats treated with the G. verum extract (500 mg/kg body weight per os) for 4 weeks. At the end of the treatment, in vivo cardiac function was assessed by echocardiography. Rats were sacrificed and blood samples were taken for spectrophotometric determination of systemic redox state. Hearts from all rats were isolated and retrogradely perfused according to the Langendorff technique. After a stabilization period, hearts were subjected to 20-minute ischemia, followed by 30-minute reperfusion. Levels of prooxidants were spectrophotometrically measured in coronary venous effluent, while antioxidant enzymes activity was assessed in heart tissue. Cell morphology was evaluated by hematoxylin and eosin (HE) staining. 4-week treatment with G. verum extract alleviated left ventricular hypertrophy and considerably improved in vivo cardiac function. Furthermore, G. verum extract preserved cardiac contractility, systolic function, and coronary vasodilatory response after ischemia. Moreover, it alleviated I/R-induced structural damage of the heart. Additionally, G. verum extract led to a drop in the generation of most of the measured prooxidants, thus mitigating cardiac oxidative damage. Promising potential of G. verum in the present study may be a basis for further researches which would fully clarify the mechanisms through which this plant species triggers cardioprotection.

The impact of aerobic and anaerobic training regimes on blood pressure in normotensive and hypertensive rats: focus on redox changes.

This study was aimed to assess the impact of aerobic and anaerobic type of exercise on blood pressure and redox status in normotensive and hypertensive rats. After 1 week of preconditioning feeding and 1 week of preconditioning running regimen, Wistar albino rats (n = 72; bw: 270 ± 50 g) were randomly assigned to three groups according to running protocol (high-intensity interval training (HIIT) or moderate-intensity training (MIT)): sedentary control, MIT, HIIT; spontaneous hypertensive sedentary control (SHR), SHR + MIT and SHR + HIIT. Blood pressure (BP) measurement was performed by a tail-cuff noninvasive method BP system. After 48 h of rest following the final training, the rats were fasted for 24 h and sacrificed under ketamine/xylazine anesthesia and blood samples were collected. The level of the next prooxidants were measured: superoxide anion radical (O2-); hydrogen peroxide (H2O2); nitrite level (NO2-) and index of lipid peroxidation (thiobarbituric acid reactive substances), and the activity of antioxidative enzymes: reduced glutathione (GSH) superoxide dismutase (SOD) and catalase (CAT) activity. After the last week of running, HIIT strongly affected SP, DP, and HR in SHR rats compared to other hypertensive rats, as well as after MIT in normotensive conditions. We have found that HIIT training protocol induced a higher increase of O2- and H2O2 as compared to MIT. Findings of the present study pointed out that contrary to normotensive conditions, in hypertensive conditions both training regimes reduced the BP levels, which was more prominent in case of HIIT. In addition, MIT seems to be connected with milder disturbance of pro-oxidant production and better antioxidant response.