Postnatal heart development is characterized by critical periods of heart remodeling. In order to characterize the changes in the lipophilic fraction induced by free radicals, fatty acids and t heir oxidized products, lipofuscin -like pigments (LFP), were investigated. Fatty acids were analyz ed by gas chromatography and LFP were studied by fluorescence techniques. A fluorophore characterized by spectral methods was further resolved by HPLC. Major changes in the composition of fatty acids occurred immediately after birth and then during maturation. Fluorescence of LFP changed markedly on postnatal days 1, 4, 8, and 14, and differed from the adult animals. LFP comprise several fluorophores that were present since fetal state till adulthood. No new major fluorophores were formed during development, just the abundances of individual fluorophores have been modulated which produced changes in the shape of the spectral arrays. HPLC resolved the fluorophore with excitation maximum at 360 nm and emission maximum at 410 nm. New chromatographically distinct species appeared immediately on postnatal day 1, and then on days 30 and 60. Consumption of polyunsaturated fatty acids immediately after birth and subseque nt formation of LFP suggests that oxidative stress is involved in normal heart development., J. Wilhelm, J. Ivica, Z. Veselská, J. Uhlík, L. Vajner., and Obsahuje bibliografii
Nitric oxide (NO) may play a role in the pathophysiology of excitotoxicity. It is also possible that increase in Ca2+ overload and NO-mediated events are involved in neuronal loss during excitotoxicity. Using nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry, we have investigated the effects of melatonin on NADPH-d positive hippocampal neurons after kainic acid (KA) induced excitotoxicity in female rats of Wistar strain. Cytosolic Ca2+ (free calcium) in all the respective experimental groups was also studied. Kainic acid was administered, with a single dose of 10 mg/kg/bw (body weight) to the animals. KA treated rats were given melatonin at a dose of 20 mg/kg/bw (for 14 day). On the last day of treatment, animals were transcardially perfused with 4 % paraformaldehyde under deep thiopental anaesthesia. Cryostat sections (20 µm) were cut and stained for NADPH-d positive neurons. KA exposed animals showed a significantly increased number of NADPH-d positive neurons in the dorsal and ventral blade of the dentate gyrus (DG), hilus, CA1 and CA3 area of hippocampus, with a parallel increase in intracellular free Ca2+ ion concentration, as compared to the control group. KA + melatonin-treated animal groups showed reduced number of NADPH-d positive neurons in DG, hilus, CA1 and CA3 areas and a decline in cytosolic Ca2+ concentration, as compared to KA treated group. Our study suggests that the enhanced levels of cytosolic Ca2+ and nitric oxide (NO) play an important role in kainate induced excitotoxicity. Inhibition of NO production may be another means whereby melatonin can reduce oxidative damage and seems to play important role in neuroprotection., A. Jain, ... [et al.]., and Obsahuje seznam literatury
Free radicals and proinflammatory cytokines from phagocytes have been implicated in the pathogenesis of endotoxic shock, a disease with high mortality caused by Gram-negative bacterial endotoxin. In the present study, male BALB/c and Swiss mice received intraperitoneally lipopolysaccharide (LPS) at 100 mg/kg and 150 mg/kg, respectively, that led to a lethal endotoxic shock (100 % of mortality before 30 h). Swiss mice injected with 100 mg/kg, that did not show lethal endotoxic shock, were also studied. Peritoneal macrophages were obtained from animals at 2, 4, 12 or 24 h after injection of LPS or saline (control) solutions. Superoxide anion and tumor necrosis factor (TNFα) production were determined in these cells as well as other functions such as adherence capacity, chemotaxis and phagocytosis. The increase in superoxide anion production after endotoxin injection was higher in cells from mice with lethal shock than in those with non-lethal shock. However, the enhancement of TNFα production was similar in all cases, although in Swiss mice the highest levels of TNFα were observed at 1.5 h after endotoxin injection, while in BALB/c mice they occurred at 2 h after LPS injection. This oxidative stress was also revealed by the other functions analyzed, since adherence to substrate and phagocytosis were stimulated and chemotaxis was decreased after endotoxin injection as compared to controls, the differences being even more significant in animals with lethal shock. These data suggest that these changes, mainly the increased production of free radicals even more than the TNFα release, could be involved in mouse mortality caused by LPS., V. M. Víctor, M. de la Fuente., and Obsahuje bibliografii
Tissue differentiation and proliferation throughout fetal development interconnect with changes in the oxidative phosphorylation system (OXPHOS) on the cellular level. Reevaluation of the expression data revealed a significant increase in COX4 and MTATP6 liver transcription levels after the 22nd gestational week (GW) which inspired us to characterize its functional impact. Specific activities of cytochrome c oxidase (COX), citrate synthase (CS), succinate-coenzyme Q reductase (SQR) and mtDNA determined by spectrophotometry and RT-PCR were studied in a set of 25 liver and 18 skeletal muscle samples at 13th to 29th GW. Additionally, liver hematopoiesis (LH) was surveyed by light microscopy. The mtDNA content positively correlated with the gestational age only in the liver. The activities of COX, CS and SQR in both liver and muscle isolated mitochondria significantly decreased after the 22nd GW in comparison with earlier GW. A continuous decline of LH, not correlating with the documented OXPHOS-specific activities, was observed from the 14th to the 24th GW indicating their exclusive reflection of liver tissue processes. Two apparently contradictory processes of increasing mtDNA transcription and decreasing OXPHOS-specific activities seem to be indispensable for rapid postnatal adaptation to high energy demands. The inadequate capacity of mitochondrial energy production may be an important factor in the mortality of children born before the critical developmental point of the 22nd GW., H. Kolarová, J. Křížová, M. Hůlková, H. Hansiková, H. Hůlková, V. Smid, J. Zeman, T. Honzík, M. Tesarová., and Seznam literatury
Quantitative and qualitative changes of serum proteins, apart from glycation, have not been sufficiently studied in streptozotocin-induced diabetic rats (D), the most common experimental model for diabetes. Thus, we decided to analyze the serum of diabetic rats by concanavalin A-blotting in comparison with rats with acute inflammation induced by fermented yeast (Y), in which characteristic alterations of serum proteins have been described. Two months after the streptozotocin treatment, the blood glucose levels were highly elevated (456± 24 vs. 124± 10 mg/dl, p<0.001, n=12), the body weight was significantly lower than normal (279± 10 vs. 392± 6 g, p<0.001, n=12), and serum proteins appeared to be highly glycated (p<0.001) when analyzed by the fructosamine assay, without any significant change in the total serum protein concentration. Analysis by concanavalin A-blotting, revealed a significant decrease of a1-inhibitor-3 (a1-I3, p<0.05) and an increase of the b chain of haptoglobin (b-Hp, p<0.05) in both D and Y rats (n=3) compared with control animals. However, acute inflammation caused a marked rise of two prominent acute phase proteins, a2-macroglobulin and hemopexin, which did not change appreciably in diabetic rats. Further work will be necessary to evaluate the physiopathological significance of these phenomena which could result from changes of both concentration and glycosylation of the aforementioned proteins., L. Saso, P. Tommasino, G. Italiano, E. Grippa, M.G. Leone, M.T. Gatto, B. Silvestrini., and Obsahuje bibliografii
Specific neuronal populations are known to express calcium binding proteins (CBP) such as calbindin (CB), parvalbumin (PV) and calretinin (CR). These CBP can act as calcium buffers that modify spatiotemporal characteristics of intracellular calcium transients and affect calcium homeostasis in neurons. It was recently shown that changes in neuronal CBP expression can have significant modulatory effect on synaptic transmission. Spinothalamic tract (STT) neurons form a major nociceptive pathway and they become sensitized after peripheral inflammation. In our experiments, expression of CBP in STT neurons was studied in a model of unilateral acute knee joint arthritis in rats. Altogether 377, 374 and 358 STT neurons in the segments L3-4 were evaluated for the presence of CB, PV and CR. On the contralateral (control) side 11 %, 9 % and 47 % of the retrogradely labeled STT ne urons expressed CB, PV and CR, respectively. On the ipsilateral (arthritic) side there was significantly more CB (23 %) and PV (25 %) expressing STT neurons, while the number of CR positive neurons (50 %) did not differ. Our results show increased expression of fast (CB) and slow (PV) calcium binding proteins in STT neurons after induction of experimental arthritis. This suggests that change in CBP expression could have a significant effect on calcium homeostasis and possibly modulation of synaptic activity in STT neurons., D. Sojka, G. Zacharova, D. Spicarova, J. Palecek., and Obsahuje bibliografii
Ozone depletion leads to an increase in UV rays of solar radiation reaching the surface of the Earth which is harmful to biological systems. Of the eye, the cornea is directly open to increased amount of UV rays of which mainly UVB rays are capable to induce reactive oxygen species damaging the cells. Previous studies showed that the irradiation of the cornea with UVB rays leads to morphological as well as metabolic disturbances of the cornea. Also, corneal hydration and corneal light absorption are increased after UVB rays. These changes were observed after five days of repeated irradiation of the cornea with UVB rays. The aim of the present paper was to examine how early the changes of corneal hydration and light absorption occur after UVB irradiation. The rabbit corneas were irradiated with UVB rays for one, two, three or four days. Corneal light absorption was examined spectrophotometrically and corneal hydration measured by pachymeter (as corneal thickness). Results show that changes of corneal hydration and light absorption appear early after UVB irradiation and increase along with the number of irradiations. In conclusion, irradiation of the rabbit cornea with UVB rays leads to harmful changes of its optical properties., Č. Čejka ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
a1_Gastric lipase (GL) plays an important role in emulsification and digestion of food fat. Lipids are components of the hydrophobic mucus and mucosa barrier. Damage of the gastric mucosa may therefore be related to changes in the lipid content and GL activity. In the present paper, we studied the effect of administration of a single dose of 96 % ethanol (E) and indomethacin 20 mg.kg-1 (IND) on the activity of GL and on the concentrations of nonesterified fatty acids (NEFA) and triacylglycerols (TG) in the gastric mucosa of rats. Furthermore, we studied how these changes are affected by allopurinol (ALO), pentoxifylline (PX) and L-DOPA pretreatment 30 min before administration of E or IND. The effect of sialoadenectomy (SA) on these parameters was also evaluated. We found: 1) significant (p<0.01) inhibition of GL activity after administration of E and IND and also ALO, as well as after pretreatment with ALO before E and PX before IND. L-DOPA administered alone stimulated GL activity, but its administration before IND significantly (p<0.01) inhibited this enzymatic activity. GL activity was decreased to the threshold values in SA rats and after administration of E to SA animals. 2) NEFA concentrations were decreased after E and increased significantly (p<0.01) after IND administration. A marked significant (p<0.01) decrease in NEFA was found after PX and L-DOPA administration. The administration of ALO also lowered the concentration of NEFA. Pretreatment by drugs before E and IND resulted in a significant increase of NEFA in comparison with the drugs given alone (p<0.05 for ALO + E; p<0.01 for PX + IND). 3) TG were also decreased in all experimental groups in comparison with the control group, i.e. after E and IND, after ALO and SA and also after pretreatment by ALO before E. The concentration of TG decreased after PX, significantly (p<0.05) after L-DOPA and after pretreatment by PX before IND., a2_Pretreatment by ALO before E and L-DOPA before IND resulted in the increase of TG in comparison with drugs alone. Thus, these results suggest certain protective effect of pretreatment with ALO, PX and L-DOPA against the E- and IND-induced decrease in NEFA and TG during injury of the gastric mucosa. On the other hand, inhibition of GL activity was also apparent after administration of these drugs before E and IND, which suggest presence of a persisting impairment of lipid digestion in the stomach., A. Sedláková, A. Kohút, M. Šarišský., and Obsahuje bibliografii
The effect of ethanol on the structural development of the central nervous system was studied in offspring of Wistar rats, drinking 20 % ethanol during pregnancy and till the 28th day of their postnatal life. The structural changes in the hippocampus and dentate gyrus were analyzed at the age of 18, 35 and 90 days. A lower width of pyramidal and granular cell layers, cell extinction and fragmentation of numerous nuclei were found in all experimental animals compared to control animals. The extent of neural cell loss was similar in all monitored areas and in all age groups. At the age of 18 and 35 days, the degenerating cells were observed in the CA1 and CA3 area of the hippocampus and in the ventral and dorsal blade of the dentate gyrus. Numerous glial cells replaced the neuronal population of this region. Some degenerating cells with fragmented nuclei were observed at the age of 90 days. Our experiments confirmed the vulnerability of the developing central nervous system by ethanol intake during the perinatal period and revealed a long-lasting degeneration process in the hippocampus and dentate gyrus., M. Milotová, V. Riljak, K. Jandová, J. Bortelová, D. Marešová, K. Pokorný, M. Langmeier., and Obsahuje bibliografii a bibliografické odkazy
The effects of various stressors on insulin receptors in adipose, liver and skeletal muscle tissues were studied in rats exposed to acute or repeated stress. Adult male rats were exposed to immobilization (IMO) for 2.5 hours daily for 1, 7 and 42 days, or to hypokinesia (HK) for 1, 7 and 21 days. We determined the values of specific insulin binding (SIB) and insulin receptor binding capacity (IR) of plasma cell membranes from adipose, liver and muscle tissue (IMO groups), or insulin binding to isolated adipocytes and hepatocytes (HK groups). A significant decrease of SIB and IR was observed in rats exposed to acute stress (1x IMO) in muscle, adipose and liver tissues. However, in animals exposed to repeated stress (7x and 42x IMO), SIB and IR were diminished in the muscle tissue, whereas no significant changes were noted in the liver and adipose tissue. When tissue samples were collected 3-24 hours after exposure to IMO stress, no changes of SIB and IR were found in liver and adipose tissue, but insulin binding was lowered in skeletal muscles. In animals exposed to HK for one day, a decrease of SIB and IR was found in isolated adipocytes, but no changes in insulin binding were noted in the liver tissue. In rats exposed to HK for 7 and 21 days, values of IR were similar as in control group. Our results indicate a) the different changes of IR in the liver, fat and muscle tissues after exposure to stress situations, b) a long-term decrease of insulin binding in muscles of rats exposed to repeated IMO stress, and c) the return of reduced SIB and IR (induced by acute stress) to control values in the liver and adipose tissue after a short recovery period., L. Macho, M. Ficková, Š. Zórad, R. Kvetňanský., and Obsahuje bibliografii