Alcohol-related acute pancreatitis can be mediated by a combination of alcohol and fatty acids (fatty acid ethyl esters) and is initiated by a sustained elevation of the Ca 2+ concentration inside pancreatic acinar cells ([Ca 2+ ] i ), due to excessive release of Ca 2+ stored inside the cells followed by Ca 2+ entry from the interstitial fluid. The sustained [Ca 2+ ] i elevation activates intracellular digestive proenzymes resulting in necrosis and inflammation. We tested the hypothesis that pharmacological blockade of store-operated or Ca 2+ release-activated Ca 2+ channels (CRAC) would prevent sustained elevation of [Ca 2+ ] i and therefore protease activation and necrosis. In isolated mouse pancreatic acinar cells, CRAC channels were activated by blocking Ca 2+ ATPase pumps in the endoplasmic reticulum with thapsigargin in the absence of external Ca 2+ . Ca 2+ entry then occurred upon admission of Ca 2+ to the extracellular solution. The CRAC channel blocker developed by GlaxoSmithKline, GSK-7975A, inhibited store-operated Ca 2+ entry in a concentrationdependent manner within the range of 1 to 50 μM (IC 50 = 3.4 μM), but had little or no effect on the physiological Ca 2+ spiking evoked by acetylcholine or cholecystokinin. Palmitoleic acid ethyl ester (100 μM), an important mediator of alcohol-related pancreatitis, evoked a sustained elevation of [Ca 2+ ] i , which was markedly reduced by CRAC blockade. Importantly, the palmitoleic acid ethyl ester-induced trypsin and protease activity as well as necrosis were almost abolished by blocking CRAC channels. There is currently no specific treatment of pancreatitis, but our data show that pharmacological CRAC blockade is highly effective against toxic [Ca 2+ ] i elevation, necrosis, and trypsin/protease activity and therefore has potential to effectively treat pancreatitis.capacitative Ca 2+ entry | alcohol metabolite | pancreas | hepatocyte Ca 2+ entry | AR42JA cute pancreatitis is a human disease mostly caused by alcohol abuse or complications from biliary disease. In this disease, against which there is currently no effective therapy, digestive proenzymes are prematurely activated inside the acinar cells leading to autodigestion and necrosis (1-3). Intracellular Ca 2+ plays a critical role in the initiation of this disease process (2-4), but intracellular Ca 2+ also plays a critical role in the physiological regulation of the normal exocytotic secretion of the digestive proenzymes (5).The pancreatic acinar cells are capable of generating multiple patterns of cytosolic Ca 2+ signals depending on the type and concentration of the stimulating agent (5). The physiological Ca 2+ signals regulating secretion-evoked by the neurotransmitter acetylcholine (ACh) or the hormone cholecystokinin (CCK)-consist of repetitive short-lasting rises in the cytosolic Ca 2+ concentration ([Ca 2+ ] i ). These are mostly confined to the apical area, in which the secretory (zymogen) granules (ZGs) are concentrated, by a belt of perigranular mitochondria operating as a firewall against...
Bafilomycin A1 potentiates the effect of NAADP by inhibiting the mitochondrial energetic process in lymphoma cells and activity of Na /K -ATPase. The obtained data show promising possibility to use bafilomycin A1 and NAADP as chemotherapeutic agents for lymphoma cells treatment. This is important because lymphomas are seventh most common form of cancer. Today the lymphoma mortality is 15% to 30%, whereas the effectiveness of malignant neoplasms treatment is less than 50%.
Ключові слова: пухлинні клітини, лімфома NK/Ly мишей, активність АТФ-аз, НААДФ, Na + ,K +-помпа, Са 2+-помпа ПМ і ЕПР. ВСТУП Останнім часом у терапії пухлин значну увагу приділяють таким клітинним "мішеням", як системи активного транспорту йонів [4; 10; 15]. Зокрема, встановлено,
Recycling of the endo-lysosomal organelles occur by permanent in the cell. This store is thought to be the acidic store because V-type of H +-ATPase is responsible for their acidification. Bafilomycine A1 is a selective inhibitor of vacuolar H + ATPase, and is often used as anticancer drug. However, it is not clear if applying of bafilomycine A1 is safe for normal cells. Endo-lysosomes are important cellular Ca 2+ storage, sensitive to nicotinic acid adenine dinucleotide phosphate (NAADP). Hepatocytes were shown to have NAADP-sensitive acidic store. But the correlation between acidic store and endoplasmatic reticulum or plasmatic membrane during endo-lysosomal organelles recycling and fusion is still unknown. The main goal of this study was to examine influence of bafilomycine A1 and NAADP on activity of Na + /K +-ATPase, basal Mg 2+-ATPase and Ca 2+-ATPase of plasmatic membrane (PM) and endoplasmatic reticulum (ER) for better understanding of the relationship between acidic organelles and PM/ER. Besides possibility of bafilomycine A1 applying as anticancer drug is examined. All experiments were conducted using rat liver postmitochondrial fraction. It was shown that SERCA activity is increasing under bafilomycine A1 presence, as well as NAADP. At the same time, changes in PMCA activity was not found. Preincubation of rat liver postmitochondrial fraction with bafilomycine A1 completely prevented NAADPinduced increasing of SERCA activity. Bafilomycine A1 decreased activity of Na + /K +-ATPase and amplificated NAADP-induced decreasing of this pump. Applying of NAADP caused more intensive decrease in Na + /K +-ATPase activity after preincubation of this fraction with bafilomycine A1. It was also shown that bafilomycine A1 caused increasing of basal Mg 2+-ATPase activity and NAADP intensify bafilomycine A1-induced changes of function of this pump. These effects are realized due to changes of pH inside the endolysosomal ogranels, acidification of incubation medium, as well as calcium concentration in local contact sites. A conclusion was made that NAADP-sensitive store is bafilomycine A1-sensitive, which also has direct contact sites to ER, but not to PM. Besides, existing of NAADPsensitive, but bafilomycine-insensitive store in this fraction is supposed, which is more likely represented by endosomes. So, applying bafilomycine A1 in anticancer therapy may cause a damage of endo-lysosomal organelles recycling in healthy cells.
The aim is to investigate the effect of bile acids on the ATPase activity of the colon mucosa in patients with overweight and irritable bowel syndrome (IBS). Materials and methods: Completely examined 12 patients with IBS and overweight.We estimated the ATPase activity of colon mucous of the patients with IBSspectrophotometrically by determined the content of orthophosphate that was released after ATP hydrolysis. We studied the effect of 3-sulphate of taurolitocholate (TLC-S) on specific activities of Na+/ K+-ATPase, Ca2+-ATPase of endoplasmatic reticulum (EPR),Ca2+-ATPase of plasmatic membrane (PM) and basal Mg2+-ATPase of postmitochondrial subcellular fraction of colon mucous of the patients with IBS. Results: We establishedthe specific activities of Na+/K+-ATPase, Ca2+-ATPase of EPR,Ca2+-ATPase of PM and basal Mg2+-ATPase. Therewere(6.06 ± 1.61), (5.88 ± 1.19), (8.86 ± 1.56) (6.44 ± 2.02)μmol Pi/ mg protein per hour, respectively. TLC-S (50 μM) did not causedany change of Na+/K+-ATPase , as well as Ca2+-ATPasesactivities, but statistically significant increased activity of Mg2+-ATPase of postmitochondrial subcellular fraction of colon mucous of the patients with IBS by 4 fold. Conclusions: TLC-S increased basal Mg2+-ATPase in the postmitochondrial fraction of colon mucous of the patients with overweight and IBS, but had no effect on Na+/K+-ATPase and Ca2+-ATPases activities. It has been suggested that activation of basal Mg2+-ATPase under by TLC-S may indicates the role of the endo-lysosomal system of epitheliocytes of colon mucous in developing of pathology IBS.
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