Magdaléna Holečková

The serum levels of calcium, magnesium, iron and zinc in patients with recurrent vulvovaginal candidosis during attack, remission and in healthy controls.

The real cause of recurrent vulvovaginal candidosis (RVVC) is concealed and the etiopathogenesis of this disease remains to be determined. In a cohort study, concentrations of metals in 44 patients with RVVC and 30 healthy age‐matched women were measured and compared. The concentrations of serum calcium (Ca), magnesium (Mg) and iron (Fe) were measured photometrically, the zinc (Zn) levels were determined using flame atomic absorption spectrometry. For statistical analysis were used the Students t‐tests (paired analysis for attack vs. remission; non‐paired analysis for patient vs. control). Although all measured metals were within normal ranges the patients with RVVC had in contrast to the healthy controls significantly lower levels of serum Ca, Mg and Zn and insignificantly higher levels of Fe. These relative changes may contribute to the development of attacks in patients with RVVC.

Cardiac biomarkers in a model of acute catecholamine cardiotoxicity

Coronary heart disease and in particular its most serious form — acute myocardial infarction (AMI) — represents the most common cause of mortality in developed countries. Better prognosis may be achieved by understanding the etiopathogenetic mechanisms of AMI. Therefore, a catecholamine model of myocardial injury, which has appeared to be very similar to AMI in human in some aspect, was used. Male Wistar:Han rats were randomly divided into two groups: control group (saline) and isoprenaline group (ISO; synthetic catecholamine, 100 mg.kg— 1 subcutaneously [s.c.]). After 24 hours, functional parameters were measured, biochemical markers in the blood and metals content in the heart tissue were analysed and histological examination was performed. ISO caused marked myocardial injury that was associated with myocardial calcium overload. Close correlation between myocardial impairment (i.e. serum TnT, stroke volume index and wet ventricles weight) and the levels of myocardial calcium was observed. Direct reactive oxygen species (ROS) involvement was documented only by non-significant increase in malonyldialdehyde 24 hours after ISO injury. Moreover, myocardial element analysis revealed no significant changes as for the content of zinc and iron while selenium and copper increased in the ISO group although it reached statistical significance only for the latter.

Direct administration of rutin does not protect against catecholamine cardiotoxicity.

High levels of catecholamines are cardiotoxic and may trigger acute myocardial infarction (AMI). Similarly, the synthetic catecholamine isoprenaline (ISO) evokes a pathological state similar to AMI. During AMI there is a marked increase of free iron and copper which are crucial catalysts of reactive oxygen species formation. Rutin, a natural flavonoid glycoside possessing free radical scavenging and iron/copper chelating activity, may therefore be potentially useful in reduction of catecholamine cardiotoxicity as was previously demonstrated after its long-term peroral administration. Male Wistar:Han rats received rutin (46 or 11.5 mg kg(-1) i.v.) alone or with necrogenic dose of ISO (100 mg kg(-1) s.c.). Haemodynamic parameters were measured 24h after drug application together with analysis of blood, myocardial content of elements and histological examination. Results were confirmed by cytotoxicity studies using cardiomyoblast cell line H9c2. Rutin in a dose of 46 mg kg(-1) aggravated ISO-cardiotoxicity while the dose of 11 mg kg(-1) had no effect. These unexpected results were in agreement with in vitro experiments, where co-incubation with larger concentrations of rutin significantly augmented ISO cytotoxicity. Our results, in contrast to previous studies in the literature, suggest that the reported positive effects of peroral administration of rutin were unlikely to have been mediated by rutin per se but probably by its metabolite(s) or by some other, at this moment, unknown adaptive mechanism(s), which merit further investigation.

Interference of IgM-λ paraprotein with biuret-type assay for total serum protein quantification

Milos Tichy*, Bedrich Friedecky, Marek Budina, Vladimir Maisnar, Tomas Buchler, Magdalena Holeckova, Dagmar Gotzmannova and Vladimir Palicka 1 Institute of Clinical Biochemistry and Diagnostics, Charles University Hospital, Hradec Králové, Czech Republic 2 SEKK, Pardubice, Czech Republic 3 2nd Department of Internal Medicine, Division of Clinical Hematology, Charles University Hospital, Hradec Králové, Czech Republic 4 Department of Oncology, Thomayer University Hospital and 1st Faculty of Medicine, Charles University, Prague, Czech Republic 5 Laborex, Ostrava, Czech Republic

Common biomarkers of oxidative stress do not reflect cardiovascular dys/function in rats

BACKGROUND Predicting cardiovascular events remains challenging despite the range of known biomarkers. AIM To establish relationships between various biochemical and functional parameters of the cardiovascular system. METHOD The relationship between cardiovascular dys/function and various biomarkers was examined in 145 experimental rats half of which received isoprenaline 100 mg/kg s.c. to induce cardiac impairment. RESULTS Serum concentration of cardiac troponin T (cTnT), a known marker of cardiac derangement, correlated strongly with degree of myocardial injury (e.g. calcium overload, stroke volume) but correlations between cTnT and oxidative stress parameters were weak (for glutathione and vitamin C) or not found (for serum vitamin E and plasma thiobarbituric acid reactive substances levels). Relationships between cTnT and other parameters were exponential with the exception of myocardial calcium, where a power function was found. CONCLUSIONS Commonly used biomarkers of oxidative stress cannot reliably predict cardiovascular dys/function in experimental rats.

Protective Effects of D-Penicillamine on Catecholamine-Induced Myocardial Injury

Iron and copper release participates in the myocardial injury under ischemic conditions and hence protection might be achieved by iron chelators. Data on copper chelation are, however, sparse. The effect of the clinically used copper chelator D-penicillamine in the catecholamine model of acute myocardial injury was tested in cardiomyoblast cell line H9c2 and in Wistar Han rats. D-Penicillamine had a protective effect against catecholamine-induced injury both in vitro and in vivo. It protected H9c2 cells against the catecholamine-induced viability loss in a dose-dependent manner. In animals, both intravenous D-penicillamine doses of 11 (low) and 44 mg/kg (high) decreased the mortality caused by s.c. isoprenaline (100 mg/kg) from 36% to 14% and 22%, respectively. However, whereas the low D-penicillamine dose decreased the release of cardiac troponin T (specific marker of myocardial injury), the high dose resulted in an increase. Interestingly, the high dose led to a marked elevation in plasma vitamin C. This might be related to potentiation of oxidative stress, as suggested by additional in vitro experiments with D-penicillamine (iron reduction and the Fenton reaction). In conclusion, D-penicillamine has protective potential against catecholamine-induced cardiotoxicity; however the optimal dose selection seems to be crucial for further application.

Myocardial elements content and cardiac function after repeated i.v. administration of DMPS in rabbits

1 A dithiol chelating agent-2,3-dimercapto-1-propane-sulphonate (DMPS)- may be administered in acute or chronic intoxication with certain heavy metals (e.g. cadmium, cobalt, lead) that may cause cardiotoxicity. 2 DMPS can act as a depleter of physiologically important elements (e.g. potassium, magnesium, calcium) in various tissues including cardiac one. The possibility of subsequent alteration in cardiac function cannot be excluded. 3 Changes in the myocardial concentration of the abovementioned elements at the end of the experiment and cardiac function were studied during repeated I.V. administration of DMPS as single doses of 50 mg/kg/ week for 10 weeks in rabbits. Biochemical, haemato-logical and histological examinations were also performed. 4 Most of the measured parameters were not affected by the repeated administration of DMPS. A significant decrease in magnesium and a near significant decrease in calcium in cardiac muscle was not accompanied by functional or morphological changes. It is still suggested, however, that care should be taken in using DMPS for treating patients with cardiotoxicity as a result of poisoning with heavy metals.

Intravenous rutin in rat exacerbates isoprenaline-induced cardiotoxicity likely due to intracellular oxidative stress.

Objectives: Rutin, quercetin-3-O-rutinoside, a natural flavonol glycoside, has shown various in vitro benefits with potential use treating human diseases, especially cardiovascular system disorders. Antioxidant properties are assumed to underlie the majority of these benefits. Yet rutin pro-oxidant properties have been reported as well. Our research group has recently shown aggravating effects on isoprenaline (ISO)-induced cardiotoxicity in Wistar:Han rats after 24 hours. Methods: This study was designed to examine in more detail the reasons for the negative effects of rutin (11.5 and 46 mg/kg, i.v.) after administration of ISO (100 mg/kg, s.c.) in rats within 2 hours of continuous experiment and in the H9c2 cardiomyoblast-derived cell line. Results: Like our previous findings, rutin did not (11.5 or 46 mg/kg, i.v.) reduce the ISO-induced mortality within 2 hours although the lower dose significantly reduced cardiac troponin T (cTnT) and partly improved the histological findings. In contrast, the higher dose increased the mortality in comparison with solvent (1.26% w/v sodium bicarbonate). This was not caused by any specific haemodynamic disturbances. It appears to be associated with oxidative stress as rutin enhanced intracellular reactive oxygen species formation in vitro and had the tendency to increase it in vivo. Conclusions: Rutin, likely due to its pro-oxidative effects, can exacerbate catecholamine cardiotoxicity depending on the dose used.

The relationship of oxidative stress markers and parameters of myocardial function in a rat model of cardiotoxicity

Although a majority of studies related oxidative stress to cardiovascular diseases, the pathophysiological relevance has been remaining unknown. The aim of this study was to establish the relationship among different commonly used biomarkers of oxidative stress and cardiovascular dys/function in rats. A pathological state in many aspects similar to that of acute myocardial infarction was induced by administration of isoprenaline (100mg.kg(-1), s.c.) in Wistar:Han rats. Haemodynamic, biochemical and ECG parameters were measured in two sets of experiments: after 24hours and continuously during the first 2hours following the administration of isoprenaline. Serum cardiac troponin T (cTnT) correlated strongly with cardiac function, myocardial calcium levels, wet ventricles weight and relevant ECG parameters (T wave, R wave and J - junction - point amplitudes). However, only weak negative correlations were found for cTnT and total blood glutathione or serum vitamin C concentrations, while no significant associations were found with serum vitamin E and plasma TBARS. Although the oxidized form of glutathione correlated positively with heart rate, no correlation with the above-mentioned ECG parameters was found. However, correlations of in 8-isoprostane with both R wave and J-junction-point amplitudes were observed. Conclusively, more selective markers of oxidative stress may predict the functional status of the heart.