Effect of acid/base balance on H-ATPase 31 kD subunit mRNA levels in collecting duct cells

Effect of acid/base balance on H-ATPase 31 kD subunit mRNA levels in collecting duct cells. The cortical collecting duct (CCD) adapts to disturbances of acid/base balance by adjusting the direction and magnitude of its HCO3 transport. The molecular events involved in this adaptation are incompletely understood, but it seems that adaptation is accompanied by changes in the activity and intracellular distribution of the vacuolar H-ATPase. The goal of this study was to examine the effects of metabolic acidosis and alkali load on the expression of the mRNA encoding the 31 kD subunit of the vacuolar H-ATPase in rabbit CCD cells. Pairs of rabbits received either a NH4Cl load or a NaHCO3 load for 16 hours, resulting in a urinary pH of 5.53 ± 0.38 and 8.42 ± 0.10, respectively. CCD cells were isolated by immunodissection and mRNA levels of the H-ATPase 31 kD subunit and of β-actin were determined from the same cDNA samples by quantitative RT-PCR. H-ATPase mRNA levels were significantly higher in CCD cells from acidotic than alkali-loaded rabbits (2.51 ± 1.3 vs. 0.65 ± 0.2; P < 0.05). Similar differences in the H-ATPase 31 kD subunit mRNA levels were observed by Northern blotting. β-actin mRNA levels were comparable in CCD cells of the two groups. The distribution of the H-ATPase 31 kD subunit mRNA was determined among the three cell types of the CCD, that is in α- and β-intercalated cells (α-ICC and β-ICC) and principal cells (PC) isolated by fluorescence-activated cell sorting. The level of expression was comparable in α-ICCs and β-ICCs, whereas PCs contained very low levels of H-ATPase mRNA. In both α-ICC and β-ICC the levels of the 31 kD H-ATPase mRNA were significantly higher in acidotic than in alkaliloaded rabbits. These results indicate that in the rabbit CCD changes in acid/base balance not only regulate the subcellular distribution of the vacuolar H-ATPase but also alter its expression, at least at the mRNA level

Geotermikus energiatermelő rendszerek hőveszteségeinek minimalizálása = Minimalization of heat losses of geothermal systems

A hévízkutakban áramló forró víz hőmérséklet eloszlásának meghatározására számítási eljárást és az azt végrehajtó számítógépi programot dolgoztunk ki. Különösen jelentős szerepe van a hőmérséklet eloszlás alakulásában három változónak. Ezek a térfogatáram, a kút, termelésbe állítása óta eltelt időtartam, valamint a geotermikus gradiens. Megvizsgáltuk az oldatból kiváló gázok, a vízkőlerakódás és a beépített búvárszivattyú hőmérséklet befolyásoló hatását is, de ezek kevésbé jelentősek. A modell a hőszigetelés számításba vételére is alkalmas, ennek tervezéséhez is megbízható alapot jelent. A kutató munkából levonható legfontosabb következtetés, hogy az időben változó hőátviteli folyamatot a tanulmányban bemutatott fizikai-matematikai modell és az azon alapuló számítógépi program valósághűen írja le. Az algyői mező hévíztermelő kútjaiban mért hőmérséklet értékek a számítások eredményeivel jól egyeznek. Mindezek alapján elvárható, hogy az ortaházi kutakra vonatkozó modell számításokra megnyugtatóan alapozhatók a kísérleti geotermikus erőmű tervei. | A computer model is presented for predicting down-hole wellbore temperatures in flowing hot water streams. Three parameters have very strong influence to the temperature distribution: the flow rate, the duration of time since the beginning of production, and the geothermal gradient. The effects of the dissolving gases, the sealing and the built-in submersible pump were analyzed during the research. Thermal insulation of the well was also considered. Following are conclusions based on results of this investigation: Physical and mathematical concepts presented here properly model the transient heat transfer phenomena. Field temperatures can be predicted accurately by the model. Good agreement between model calculations and field data has been achieved for many geothermal wells of the Algyo area. It can be expected, that model calculations of the Ortaháza wells obtain a good prediction for the Hungarian geothermal pilot plant project