Alcohol abuse during pregnancy is a well-known factor in fetal morbidity, including smaller fetal size. We have shown that chronic hypoxia, considered the main pathogenetic factor in intrauterine growth restriction, elevates fetoplacental vascular resistance (and vasoconstrictor reactivity) and thus, presumably, reduces placental blood flow. We thus hypothesized that alcohol may affect the fetus - in addition to other mechanisms - by altering fetoplacental vascular resistance and/or reactivity. Using isolated, double-perfused rat placenta model, we found that maternal alcohol intake in the last third of gestation doubled the vasoconstrictor responses to angiotensin II but did not affect resting vascular resistance. Reactivity to acute hypoxic challenges was unchanged. Chronic maternal alcohol intake in a rat model alters fetoplacental vasculature reactivity; nevertheless, these changes do not appear as serious as other detrimental effects of alcohol on the fetus., V. Jakoubek, V. Hampl., and Obsahuje bibliografii
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
Stomach lesions induced by indomethacin (20 mg.kg'1 i.p.) and ethanol (1 ml 95 % intragastrically) were studied after a 24 hour fast in rats which had undergone sialoadenectomy. The size of the lesions was correlated with gastric HCI secretion, with gastric vascular permeability (determined from the Evans blue concentration in the stomach tissue after its i.v, administration) and with the serum gastrin level. These parameters were also studied in sialoadenectomized rats and in animals given epidermal growth factor (EOF) (50 lg.kg'1). It was found that sialoadenectomy significantly (p<0.01) raised the incidence of stomach lesions after the administration of indomethacin and also after ethanol (p<0.05). A significant increase in both basal and stimulated HCI secretion was found after sialoadenectomy. Both indomethacin and ethanol also increased gastric vascular permeability in rats not subjected to sialoadenectomy, but sialoadenectomy raised it significantly compared with the non-sialoadenectomized group. The serum gastrin levels fell after sialoadenectomy and the decrease was significant after the subsequent administration of indomethacin or ethanol.The administration of EGF to sialoadenectomized rats lowered the incidence of stomach lesions, inhibited HCI secretion and reduced vascular permeability. The lowered susceptibility of the gastric mucosa to the formation of lesions in sialoadenectomized rats given indomethacin or ethanol can be regarded as the outcome of the uptake of EGF.
The activity of lipoprotein lipase (LPL) is increased after alcohol consumption and can contribute to an increased level of HDL-cholesterol, which is considered to play a key role in the ethanol-mediated protective effect against cardiovascular disease. The increase in HDL-cholesterol concentration can be also due to an ethanol-enhanced synthesis and secretion of apolipoprotein A-I (apo A-I) from hepatocytes. Therefore, the hypothesis that ethanol consumption affects the LPL and apo A-I gene (LPL and APOA1, respectively) expression was tested in male C57BL/6 mice drinking 5 % ethanol or water and fed a standard chow or high-fat (HF) diet for 4 weeks. The LPL expression was determined in the heart, epididymal and dorsolumbal adipose tissues, the APOA1 expression in the liver. Alcohol consumption did not affect lipid and lipoprotein concentrations in the serum. The LPL expression was increased in the heart of mice given ethanol and HF diet compared to mice on chow and ethanol (p<0.001) and was also increased in epididymal fat in mice given ethanol and HF diet compared to mice on water and HF diet (p<0.05). Neither LPL expression in dorsolumbal fat nor APOA1 expression in the liver were affected by ethanol consumption. Our data suggest that ethanol consumption upregulate LPL expression in a tissue- and diet-dependent manner., E. Mudráková, J. Kovář., and Obsahuje bibiografii a bibliografické odkazy
Malotilate as a synthetic substance shares comparable hepatoprotective properties with various flavonoids. The gastroprotective effect of some flavonoids prompted us to ascertain the similar effectiveness of malotilate. The possible gastroprotectivity was examined in gastric mucosal damage in rats induced by indomethacin (20 mg.kg-1) or ethanol (96 %). Oral pretreatment with malotilate (25, 50, 100, 200 and 400 mg.kg-1) reduced the extent of lesions induced by both indomethacin and ethanol. Histological analyses also revealed a mitigating effect on the severity of gastric mucosal lesions. Similar results were obtained in the group of rats pretreated with 5 mg.kg-1 indomethacin followed by oral administration of 96 % ethanol. This finding suggests that the effect of malotilate on rat gastric mucosa is independent of endogenous prostaglandin production.
Guinea-pigs were maintained for 5 weeks on a diet containing three different concentrations of vitamin C: a) traces (none added), b) medium (0.05 % w/w) and high (0.5 % w/w). Twenty-four hours before killing the animals received one i.p. dose of 3 g ethanol per kg body weight (a model of short-term acute intoxication). In a parallel experiment which lasted 5 weeks, the animals were treated every week with two i.p. doses of 1 g ethanol per kg body weight followed bv the final acute intoxication (3 g ethanol/kg) (a model of long-term chronic alcoholization). In both experiments, the guinea-pigs with the highest tissue concentration of vitamin C proved to have significantly decreased residual levels of ethanol and acetaldehyde in the liver and the brain, a decreased activity of alanine- and aspartate aminoacyl transferases in the serum and decreased contents of triacylglycerols and cholesterol in the serum and liver in comparison with the vitamin C-unsupplemented group. The regression curve expressing vitamin C levels versus residual ethanol and acetaldehyde concentrations in the liver confirmed the highly significant negative correlation between them. Administration of the guinea-pigs with large amounts of vitamin C appears to accelerate ethanol and acetaldehyde metabolism and reduce some of their adverse health effects.
The inhibitory effect of 2 % ethanol (400 mM) in the incubation medium on several characteristics of the Na+-ATPase of basolatcral plasma membranes from rat kidney proximal tubular cells was investigated. Ethanol did not change the Km of the enzyme for Mg2+, ATP or Na + ; it did not change either the optimal pH or temperature values of the incubation medium for the enzyme to act and finally, it did not affect the apparent energy of activation of the enzyme. It was also found that 2 % ethanol produced stronger inhibition of the ATPase when it is in an activated or stimulated state, than when it is working at its lower basal level. The presented results can be explained by assuming that 2 % ethanol in the incubation medium inhibits Na +-ATPase activity by affecting the enzyme structure as well as its activating mechanism.
The review aims to summarize current knowledge on the effects of moderate alcohol consumption ( 1 standard drink a day for women; 2 drinks a day for men) on triglyceride concentration in circulation. Current evidence suggests that the relationship between alcohol consumption and triglyceridemia is J -shaped. Triglyceridemia is lowest in subjects who drink 10 -20 g/alcohol a day. Such a J -shaped association is comparable with that described for the relationship between alcohol and cardiovascular risk. On the contrary, alcohol taken with a meal increases and prolongs postprandi al triglyceridemia. Such effects of alcohol consumption may be at least partially explained by the effects of ethanol on lipoprotein lipase (LPL) activity. Long -term moderate alcohol consumption increases LPL activity, which may explain its TG -lowering effect. On the other hand, LPL activity is acutely downregulated by ethanol, which explains increased postprandial triglyceridemia., J. Kovář, K. Zemánková., and Obsahuje bibliografii