Guanidinoacetic acid provides superior cardioprotection to its combined use with betaine and (or) creatine in HIIT-trained rats.

This study aimed to determine how guanidinoacetic acid (GAA) or its combined administration with betaine (B) or creatine (C) influences the cardiac function, morphometric parameters, and redox status of rats subjected to high-intensity interval training (HIIT). This research was conducted on male Wistar albino rats exposed to HIIT for 4 weeks. The animals were randomly divided into five groups: HIIT, HIIT + GAA, HIIT + GAA + C, HIIT + GAA + B, and HIIT + GAA + C + B. After completing the training protocol, GAA (300 mg/kg), C (280 mg/kg), and B (300 mg/kg) were applied daily per os for 4 weeks. GAA supplementation in combination with HIIT significantly decreased the level of both systemic and cardiac prooxidants ( O 2 - , H2O2, NO 2 - , and thiobarbituric acid reactive substances) compared with nontreated HIIT (p < 0.05). Also, GAA treatment led to an increase in glutathione and superoxide dismutase levels. None of the treatment regimens altered cardiac function. A larger degree of cardiomyocyte hypertrophy was observed in the HIIT + GAA group, which was reflected through an increase of the cross-sectional area of 27% (p < 0.05) and that of the left ventricle wall thickness of 27% (p < 0.05). Since we showed that GAA in combination with HIIT may ameliorate oxidative stress and does not alter cardiac function, the present study is a basis for future research exploring the mechanisms of cardioprotection induced by this supplement in an HIIT scenario.

The cardioprotective effects of diallyl trisulfide on diabetic rats with ex vivo induced ischemia/reperfusion injury.

Diallyl trisulfide (DATS) is distinguished as the most potent polysulfide isolated from garlic. The aim of our study was to investigate effects of oral administration of DATS on healthy and diabetic rats, with special attention on heart function. Rats were randomly divided into four groups: CTRL (healthy rats), DATS (healthy rats treated with DATS), DM (diabetic rats), DM + DATS (diabetic rats treated with DATS). DATS (40 mg/kg of body weight) was administered every other day for 3 weeks, at the end of which rats underwent echocardiography, glycemic measurement and redox status assessment. Isolated rat hearts were subjected to 30 min global ischemia and 60 min reperfusion, after which heart tissue was counterstain with hematoxylin and eosin and cardiac Troponin T staining (cTnT), while expression of Bax, B cell lymphoma 2 (Bcl-2), caspase-3, caspase-9 and superoxide dismutase-2 were examined in the left ventricle. DATS treatment significantly reduced blood glucose levels of diabetic rats, and improved cardiac function recovery, diminished oxidation status, attenuated cardiac remodeling and inhibited myocardial apoptosis in healthy and diabetic rats. DATS treatment causes promising cardioprotective effects on ex vivo-induced ischemia/reperfusion (I/R) injury in diabetic and healthy rat heart probably mediated by inhibited myocardial apoptosis. Moreover, appropriate DATS consumption may provide potential co-therapy or prevention of hyperglycemia and various cardiac complications in rats with DM.

The perfusion of cisplatin and cisplatin structural analogues through the isolated rat heart: The effects on coronary flow and cardiodynamic parameters.

The therapeutic use of cisplatin for the treatment of solid tumours is associated with organ toxicity. Amongst those, the cardiotoxicity is an occasional but very serious and severe side effect. To prevent or reduce these negative effects, many cisplatin analogues have been synthesized and evaluated in terms of being a less toxic and more effective agent. In present study, we examined the effects of cisplatin and its three analogues in the isolated rat heart to determine whether changes in the structure of the platinum complexes (changing of carrier ligands - ethylenediamine; 1,2-diaminocyclohexane; 2,2':6',2''-terpyridine) can influence their cardiotoxic effects. The results of our research indicate that the introduction of aromatic rings in the structure of the platinum complexes has a negative influence on the heart function. Conversely, the other two examined complexes had less negative effects on heart function compared to cisplatin. Our findings may be of interest for a possible synthetic strategy of introducing a carrier ligand that will exert a less cardiotoxic effect.

Cisplatin and cisplatin analogues perfusion through isolated rat heart: the effects of acute application on oxidative stress biomarkers.

Drug-induced oxidative stress can occur in numerous tissues and organ systems (liver, kidney, ear, nervous system, and cardiovascular system). Cancer therapy with cisplatin is associated with side effects to which oxidative stress may contribute. We have compared the influences of cisplatin (reference compound) and its' analogues (dichloro(1,2-diaminocyclohexane)platinum(II) and chloro(2,2':6',2″-terpyridine)platinum(II)) in a model of isolated rat heart using the Langendorff technique. The production of oxidative stress biomarkers, antioxidant enzymes, myocardial damage, and expression of Bax, OH-1, and SODs were studied. Cisplatin and the analogues were perfused at concentration of 10-6 and 10-5 M during 30 min. The results of this study showed that examined platinum complexes had different ability to induce oxidative stress of isolated perfused rat heart. Varying the carrier ligands, such as 1,2-diaminocyclohexane and 2,2':6',2″-terpyridine, related to amino ligands (cisplatin) directly influenced the strength to induce production of oxidative stress biomarkers. Introducing 2,2':6',2″-terpyridine ligands provoked the smallest changes in antioxidant enzymes activity, lipid peroxidation, and expression of heme oxygenase-1, that undoubtedly indicated that this complex had the lowest impact on redox status in heart tissue. These findings may be useful in synthesis of novel platinum analogues with lower potential for oxidative stress induction. However, the fact that platinum complexes could induce toxic effects in the heart by other mechanisms should be taken into the consideration.

Platinum Complexes-Induced Cardiotoxicity of Isolated, Perfused Rat Heart: Comparison of Pt(II) and Pt(IV) Analogues Versus Cisplatin.

We have compared the cardiotoxicity of five platinum complexes in a model of isolated rat heart using the Langendorff technique. These effects were assessed via coronary flow (CF) and cardiac functional parameters. cis-Diamminedichloroplatinum(II) (cisplatin, CDDP), dichloro-(1,2-diaminocyclohexane)platinum(II) (Pt((II))DACHCl2), dichloro-(ethylenediamine)platinum(II) (Pt((II))ENCl2), tetrachloro-(1,2-diaminocyclohexane)platinum(IV) (Pt((IV))DACHCl4) and tetrachloro-(ethylenediamine)platinum(IV) (Pt((II))ENCl4) were perfused at increasing concentrations of 10(-8), 10(-7), 10(-6), 10(-5) and 10(-4) M during 30 min. In this paper, we report that cisplatin-induced dose-dependent effects on cardiac contractility and coronary flow both manifested as decrease in cardiac contractile force (dP/dt)max, heart rate and significant reduction in CF. Pt((II))ENCl2, Pt((IV))ENCl2 and Pt((IV))DACHCl4 did induce dose-dependent response only in case of CF. Our results could be also important for better understanding dose-dependent side effects of potential metal-based anticancer drugs.

Changes in athlete's redox state induced by habitual and unaccustomed exercise.

The purpose of this study was to assess the influence of sport-specific and nonspecific bouts of exercise on athletes' redox state. Blood samples were collected from 14 handball players immediately before and after graded exercise test on the cycle ergometer and handball training. Levels of superoxide anion radical (O(2) (-)), hydrogen peroxide (H(2)O(2)), nitrites (NO(2) (-)) as markers of nitric oxide, index of lipid peroxidation (TBARs), glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) activity were determined. Exercise intensity was assessed by a system for heart rate (HR) monitoring. Average athletes' HR was not significantly different between protocols, but protocols differed in total time and time and percentage of time that athletes spent in every HR zone. The laboratory exercise test induced a significant increase of H(2)O(2) and TBARs as well as the decrease of the SOD and CAT activity, while after specific handball training, levels of NO(2) (-) were increased and SOD activity decreased. It seems that unaccustomed short intensive physical activity may induce oxidative stress in trained athletes, while sport-specific activity of longer duration and proper warm-up period may not. Further research should show whether the change of protocol testing and the implementation of various supplementations and manual methods can affect the redox equilibrium.