Given the potential clinical benefit of inhibiting Na+/Ca2+ exchanger (NCX) activity dur ing myocardial ischemia reperfusion (I/R), pharmacological approaches have been pursued to both inhibit and clarify the importance of this exchanger. SEA0400 was reported to have a potent NCX selectivity. Thus, we examined the effect of SEA0400 on NCX currents and I/R induced intracellular Ca2+ overload in mouse ventricular myocytes using patch clamp techniques and fluorescence measurements. Ischemia significantly inhibited inward and outward NCX current (from -0.04±0.01nA to 0 nA at -100 mV; from 0.23±0.08 nA to 0.11±0.03 nA at +50 mV, n=7). Subsequent reperfusion not only restored the current rapidly but enhanced the current amplitude obviously, especially the outward currents (from 0.23±0.08 nA to 0.49±0.12 nA at +50 mV, n=7). [Ca2+]i, expressed as the ratio of Fura-2 fluorescence intensity, increased to 138±7 % (P<0.01) during ischemia and to 210±11 % (P<0.01) after reperfusion. The change of NCX current and the increase of [Ca 2+]i during I/R can be blocked by SEA0400 in a dose-dependent manner with an EC50 value of 31 nM and 28 nM for the inward and outward NCX current, respectively. The results suggested that SEA0400 is a potent NCX inhibitor, which can protect mouse cardiac myocytes from Ca2+ overload during I/R injuries., J. Wang, Z. Zhang, Y. Hu, X. Hou, Q. Cui, Y. Zang, C. Wang., and Obsahuje bibliografii a bibliografické odkazy
The laboratory rat, a non-photoperiodic rodent, exhibits seasonal fluctuations of melatonin. Melatonin has been found to be readily transferred from the maternal to the fetal circulation. No data exist on the possible influence of maternal pineal gland upon seasonal variations of the offspring. The aim of the present study was to asses the influence of the maternal melatonin rhythm on the offspring postnatal development of the reproductive hormones LH, FSH and prolactin. Male offspring from control, pinealectomized (PIN-X) and PIN-X + melatonin (PIN-X+MEL) mother Wistar rats were studied at 21, 31, and 60 days of age. Seasonal age-dependent variations were found for all hormones studied in control offspring but PIN-X offspring showed a tendency to have reduced duration or altered seasonal variations. Maternal melatonin treatment to PIN-X mothers partially restored the effect of pinealectomy. The chronological study of LH, FSH, and prolactin in PIN-X offspring also showed an altered pattern as compared to control-offspring. Melatonin treatment to the mothers partially restored the developmental pattern of reproductive hormones. Results of this study indicate that maternal pineal gland of the laboratory rat is involved in the seasonal postnatal development variations of reproductive hormones of the offspring., N. Vásquez, E. Díaz, C. Fernández, V. Jiménez, A. Esquifino, B. Díaz., and Obsahuje bibliografii a bibliografické odkazy
The study of ischemia/reperfusion injury included 25 patients in the acute phase of myocardial infarction (19 perfused, 6 remained non-reperfused as evaluated according to the time course of creatine kinase and CK-MB isoenzyme activity) and a control group (21 blood donors). Plasma level of malondialdehyde was followed as a marker of oxidative stress. Shortly after reperfusion (within 90 min), a transient increase of malondialdehyde concentration was detected. The return to the baseline level was achieved 6 h after the onset of therapy. The activity of a free radical scavenger enzyme, plasma glutathione peroxidase (GPx), reached its maximum 90 min after the onset of treatment and returned to the initial value after 18 h. The specificity of the GPx response was confirmed by comparing with both non-reperfused patients and the control group, where no significant increase was detected. The erythrocyte Cu,Zn-superoxide dismutase (SOD) did not exhibit significant changes during the interval studied in perfused patients, probably due to the stability of erythrocyte metabolism. In non-reperfused patients, a decrease of SOD was found during prolonged hypoxia. These results help to elucidate the mechanisms of fast activation of plasma antioxidant system during the reperfusion after myocardial infarction., V. Mužáková, R. Kanďár, P. Vojtíšek, J. Skalický, Z. Červinková., and Obsahuje bibliografii
Meconium aspiration syndrome (MAS) in newborns is characterized mainly by respiratory failure due to surfactant dysfunction and inflammation. Previous meta-analyses did not prove any effect of exogenous surfactant treatment nor glucocorticoid administration on final outcome of children with MAS despite oxygenation improvement. As we supposed there is the need to intervene in both these fields simultaneously, we evaluated therapeutic effect of combination of exogenous surfactant and selective inhibitor of NF-κB (IKK-NBD peptide). Young New Zealand rabbits were instilled by meconium suspension and treated by surfactant alone or surfactant in combination with IKK-NBD, and oxygen-ventilated for 5 h. PaO2/FiO2, oxygenation index, oxygen saturation and ventilation efficiency index were evaluated every hour; post mortem, total and differential leukocyte counts were investigated in bronchoalveolar lavage fluid (BALF) and inflammatory, oxidative and apoptotic markers were assessed in lung tissue homogenates. Exogenous surfactant combined with IKK-NBD improved oxygenation, reduced neutrophil count in BALF and levels of IL-1β, IL-6, p38 MAPK and caspase 3 in comparison with surfactant-only therapy. It seems that inhibition of inflammation may be strong supporting factor in surfactant treatment of MAS., J. Kopincova, P. Mikolka, M. Kolomaznik, P. Kosutova, A. Calkovska, D. Mokra., and Obsahuje bibliografii
a1_Young intact (18 days of age) and adult ovariectomized (OV-X, ovariectomized between 21 to 24 days of age) C3H/Di mice were used to measure the estrogenicity on the basis of the growth response of mammary epithelial structures and weight of the uterus. The percentage area of the mammary fat pad occupied by mammary epithelial structures was progressively increased by 17ß estradiol from dose 0.001 µg.d-1. The maximum effective dose of estradiol was 0.01 µg.d-1 and the dose 10 µg.d-1 of estradiol decreased mammary size to control levels (inverted-U-shaped dose-response curve). Progesterone alone progressively stimulated mammary growth in young intact females from dose 125 µg.d-1, in adult OV-X animals from dose 1000 µg.d-1. Both in young intact and adult OV-X animals, uterine weight progressively increased during estradiol treatment. Progesterone alone had no effect on uterine weight in young intact animals; in adult OV-X animals, uterine weight was increased starting from dose 250 µg.d-1. Progesterone acted synergistically with estradiol to produce higher mammary growth than that in females treated with estradiol alone. The effects of a combination of estradiol plus progesterone in the mammary gland were mimicked by norethindrone acetate and inhibited by cortisol in both young intact and adult OV-X animals. Testosterone inhibited estradiol plus progesterone stimulated growth of mammary gland only in OV-X animals, but stimulated uterine weights in both young intact and adult OV-X animals. Spleen weight and size of mammary lymph nodes were not affected by estradiol, progesterone, norethindrone acetate or testosterone, but were decreased by cortisol. Cortisol also decreased the percent area of the mammary fat pad occupied by mammary epithelial structures, but had no effect on weight of the uterus. These results show that bioassay of estrogenicity in females is not specific., a2_Mammary and uterine growth is stimulated not only by estrogens but also by progesterone and testosterone, respectively. ., J. Škarda., and Obsahuje bibliografii
a1_Young intact (18 days old) and adult castrated males of CBA and C3H/Di mice were used for measuring the estrogenicity on the basis of growth response of mammary epithelial structures and the weight of seminal vesicles. It was demonstrated that heavier young males had disproportionally heavier seminal vesicles (sex steroid-responsive organs) than small animals at day 33 of age (that is on the day when experimental animals were killed and organs dissected). However, the weight of the spleen (sex steroid-nonresponsive organ) was proportionally related to body weight. To minimize variability in hormone responsiveness, all animals were weighed at the age of 18 days and only males weighing 8±1 g were used for hormone treatment. The percentage area of mammary fat pad occupied by mammary epithelial structures was progressively increased by 17ß estradiol from dose 0.01 µg.d-1. The maximum effective dose of estradiol was 0.1 µg.d-1 and dose 10 µg.d-1 of estradiol decreased mammary size to control level (inverted-U-shaped dose-response curve). Progesterone alone stimulated mammary growth only in high doses (500 µg.d-1 and higher) in young intact males, but had no effect on mammary growth in adult castrated animals. In young intact males, estradiol alone, or progesterone alone decreased the weight of seminal vesicles. No such inhibitory effect of these hormones was noted in adult castrated males. Progesterone acted synergistically with estradiol to produce higher mammary growth compared to that in males treated with estradiol alone. In the presence of progesterone seminal vesicles weight was decreased by estradiol given in such low doses as 0.001 µg.d-1 of estradiol, which is 10 times lower than that effective in animals treated with estradiol alone. On the other hand, in the adult castrated males a combination of estradiol plus progesterone stimulated seminal vesicles weight., a2_The effects of a combination of estradiol plus progesterone in the mammary gland were mimicked by norethindrone acetate (a synthetic steroid exhibiting progestantial and estrogenic activities) and inhibited by both testosterone and cortisol. Estradiol, progesterone, norethindrone acetate, or testosterone did not affect spleen weight and size of mammary lymph nodes. However, cortisol significantly decreased not only spleen weights but also size of mammary lymph nodes. These results show that simultaneous evaluation of mammary gland growth, seminal vesicles, and the spleen weight in the same animal is suitable for bioassay of estrogenicity as well as for detection of androgenic and antiandrogenic activities., J. Škarda., and Obsahuje bibliografii
Impairment of mucosal barrier integrity of small intestine might be causative in immune-mediated gastrointestinal diseases. We tested the markers of epithelial apoptosis – cytokeratin 18 caspase-cleaved fragment (cCK-18), and enterocyte damage – intestinal fatty acid-binding protein (I-FABP) and soluble CD14 (sCD14) in sera of patients with untreated celiac disease (CLD), those on gluten-free diet (CLD-GFD), patients with autoimmune diabetes mellitus (T1D), T1D with insulitis (T1D/INS), and diabetes mellitus type 2 (T2D). We found elevated levels of cCK-18 (P<0.001), I-FABP (P<0.01) and sCD14 (P<0.05) in CLD when compared to healthy controls. However, the levels of cCK-18 (P<0.01) and I-FABP (P<0.01) in CLD-GFD were higher when compared with controls. Interestingly, elevated levels of cCK-18 and I-FABP were found in T2D and T1D (P<0.001), and T1D/INS (P<0.01, P<0.001). Twenty-two out of 43 CLD patients were seropositive for cCK-18, 19/43 for I-FABP and 11/43 for sCD14; 9/30 of T2D patients were positive for cCK-18 and 5/20 of T1D/INS for sCD14, while in controls only 3/41 were positive for cCK-18, 3/41 for I-FABP and 1/41 for sCD14. We documented for the first time seropositivity for sCD14 in CLD and potential usefulness of serum cCK-18 and I-FABP as markers of gut damage in CLD, CLD-GFD, and diabetes., I. Hoffmanová, D. Sánchez, V. Hábová, M. Anděl, L. Tučková, H. Tlaskalová-Hogenová., and Obsahuje bibliografii
a1_The decreased oxidizability of plasma lipoproteins is related to the increased vitamin E intake and its association with a relatively lower incidence of coronary heart disease has been proposed. We investigated the effect of the in vivo vitamin E supplementation on the oxidizability of serum lipids in patients with ischemic heart disease and a moderate hypercholesterolemia. Thirty-two patients (16 males and 16 postmenopausal women) participated in this placebo-controlled, randomized trial. They were treated with 400 mg vitamin E/day for 6 weeks. The copper-induced serum lipid oxidizability ex vivo was assessed by measuring conjugated diene formation at 245 nm. We also measured vitamin E, malondialdehyde (MDA) and uric acid concentrations in the plasma. Because of observed significant differences in parameters of serum lipid oxidizability (lag time and maximal rate of oxidation), plasma a-tocopherol and MDA levels between male patients and postmenopausal women supplemented with vitamin E, the results were compared between both genders. Six weeks of vitamin E supplementation significantly increased plasma vitamin E levels (by 87 %) in male patients but in postmenopausal women only by 34 %. Concomitantly with increased plasma levels of vitamin E the decrease in plasma MDA levels was observed in male patients (decrease by 20 %; p=0.008), but in postmenopausal women the decrease did not attain statistical significance. Plasma uric acid levels were not apparently changed in placebo or vitamin E supplemented groups of patients. The changes in ex vivo serum lipid oxidizability after vitamin E, supplementation have shown a significantly prolonged lag time (by 11 %; p=0.048) and lowered rate of lipid oxidation (by 21 %; p=0.004) in male patients in comparison with postmenopausal women., a2_Linear regression analysis revealed a significant correlation between plasma vitamin E levels and the lag time (r=0.77; p=0.03) and the maximal rate of serum lipid oxidation (r=-0.70; p=0.05) in male patients. However, in postmenopausal women the correlations were not significant. We conclude that 400 mg vitamin E/day supplementation in patients with ischemic heart disease and a moderate hypercholesterolemia influenced favorably ex vivo serum lipid oxidation of male patients when compared with postmenopausal women. The observed differences between both genders could be useful in the selection of the effective vitamin E doses in the prevention of coronary heart disease., A. Nagyová, V. Mongiellová, Z. Krivošíková, P. Blažíček, V. Spustová, M. Gajdoš, R. Dzúrik., and Obsahuje bibliografii
Ghrelin is a new endogenous ligand for the growth hormone secretagogue receptor. It activates the release of growth hormone from the pituitary and it also participates in the regulation of energy homeostasis. The aim of the study was to characterize changes in serum ghrelin levels in obese subjects and their relationship to the serum levels of leptin and soluble leptin receptor. Eight obese patients (6 women and 2 men) with body mass index (BMI) 40.313.4 kg.m-2 and eight healthy controls (5 women and 3 men) with BMI 22.7±1.3 kg.m-2 were examined. The ghrelin serum levels (165.0±58.1 vs. 343.37±81.96; p<0.001) and soluble leptin receptor serum levels (7.25±3.44 vs. 21.80±4.99; p<0.0001) were significantly lower in obese patients. The leptin serum levels (23.45±12.90 vs. 6.41±2.96; p<0.005) were significantly higher compared to the lean subject group. In both measured groups the levels of serum leptin significantly positively correlated with BMI. We proved a significantly lower serum ghrelin levels in the group of obese patients in comparison with the control group., M. Rosická, M. Kršek, M. Matoulek, Z. Jarkovská, J. Marek, V. Justová, Z. Lacinová., and Obsahuje bibliografii