OSR1-sensitive small intestinal Na+ transport

2012 ◽  
Vol 303 (11) ◽  
pp. G1212-G1219 ◽  
Author(s):  
Venkanna Pasham ◽  
Ganesh Pathare ◽  
Abul Fajol ◽  
Rexhep Rexhepaj ◽  
Diana Michael ◽  
...  
Keyword(s):  
Ussing Chamber ◽  
Plasma Corticosterone ◽  
Salt Transport ◽  
Protein Abundance ◽  
Cytosolic Ph ◽  
Small Intestinal ◽  
The Difference ◽  
Renal Tubular ◽  
Nhe3 Inhibitor

The oxidative stress responsive kinase 1 (OSR1) contributes to WNK (with no K)-dependent regulation of renal tubular salt transport, renal salt excretion, and blood pressure. Little is known, however, about a role of OSR1 in the regulation of intestinal salt transport. The present study thus explored whether OSR1 is expressed in intestinal tissue and whether small intestinal Na+/H+ exchanger (NHE), small intestinal Na+-glucose cotransport (SGLT1), and/or colonic epithelium Na+ channel (ENaC) differ between knockin mice carrying one allele of WNK-resistant OSR1 ( osr1 +/KI) and wild-type mice ( osr1 +/+). OSR1 protein abundance was determined by Western blotting, cytosolic pH from BCECF fluorescence, NHE activity from Na+-dependent realkalinization following an ammonium pulse, SGLT1 activity from glucose-induced current, and colonic ENaC activity from amiloride-sensitive transepithelial current in Ussing chamber experiments. As a result, OSR1 protein was expressed in small intestine of both osr1 +/KI mice and osr1 +/+ mice. Daily fecal Na+, K+, and H2O excretion and jejunal SGLT1 activity were lower, whereas small intestinal NHE activity and colonic ENaC activity were higher in osr1 +/KI mice than in osr1 +/+ mice. NHE3 inhibitor S-3226 significantly reduced NHE activity in both genotypes but did not abrogate the difference between the genotypes. Plasma osmolarity, serum antidiuretic hormone, plasma aldosterone, and plasma corticosterone concentrations were similar in both genotypes. Small intestinal NHE3 and colonic α-ENaC protein abundance were not significantly different between genotypes, but colonic phospho-β-ENaC (ser633) was significantly higher in osr1 +/KI mice. In conclusion, OSR1 is expressed in intestine and partial WNK insensitivity of OSR1 increases intestinal NHE activity and colonic ENaC activity.

Possible role of corticosterone in the down-regulation of the hypothalamo-hypophysial-thyroid axis in streptozotocin-induced diabetes mellitus in rats

1997 ◽  
Vol 153 (2) ◽  
pp. 259-267 ◽  
Author(s):  
G A C van Haasteren ◽  
E Sleddens-Linkels ◽  
H van Toor ◽  
W Klootwijk ◽  
F H de Jong ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Median Eminence ◽  
Plasma Corticosterone ◽  
Diabetic Rats ◽  
Type I ◽  
Thyroid Axis ◽  
Streptozotocin Induced Diabetes ◽  
The Difference

Abstract We investigated the effects of diabetes mellitus on the hypothalamo-hypophysial-thyroid axis in male (R×U) F1 and R-Amsterdam rats, which were found to respond to streptozotocin (STZ)-induced diabetes mellitus with no or marked increases, respectively, in plasma corticosterone. Males received STZ (65 mg/kg i.v.) or vehicle, and were killed 1, 2 or 3 weeks later. At all times studied, STZ-induced diabetes mellitus resulted in reduced plasma TSH, thyroxine (T4) and 3,5,3′-tri-iodothyronine (T3). Since the dialyzable T4 fraction increased after STZ, probably as a result of decreased T4-binding prealbumin, plasma free T4 was not altered during diabetes. In contrast, both free T3 and its dialyzable fraction decreased during diabetes, which was associated with an increase in T4-binding globulin. Hepatic activity of type I deiodinase decreased and T4 UDP-glucuronyltransferase increased after STZ treatment. Thus, the lowered plasma T3 during diabetes may be due to decreased hepatic T4 to T3 conversion. Median eminence content of TRH increased after STZ, suggesting that hypothalamic TRH release is reduced during diabetes and that this is not caused by impaired synthesis or axonal transport of TRH to the median eminence. Hypothalamic proTRH mRNA did not change in diabetic (R×U) F1 rats during the period of observation, but was lower in R-Amsterdam rats 3 weeks after STZ. Similarly, pituitary TSH and TSHβ mRNA had decreased in R-Amsterdam rats by 1 week after STZ treatment, but did not change in (R×U) F1 rats. The difference between the responses in diabetic R-Amsterdam and (R×U) F1 rats may be explained on the basis of plasma corticosterone levels which increased in R-Amsterdam rats only. Hypothalamic TRH content was not affected by diabetes mellitus, but the hypothalami of diabetic rats released less TRH in vitro than those of control rats. Moreover, insulin had a positive effect on TRH release in vitro. In conclusion, the reduced hypothalamic TRH release during diabetes is probably not caused by decreases in TRH synthesis or transport to the median eminence, but seems to be due to impaired TRH release from the median eminence which may be related to the lack of insulin. Inhibition of proTRH and TSHβ gene expression in diabetic R-Amsterdam rats is not a primary event but appears to be secondary to enhanced adrenal activity in these animals during diabetes. Journal of Endocrinology (1997) 153, 259–267

Plasma level and renal handling of Pi: effect of overnight fasting with and without Pi supply

1981 ◽  
Vol 241 (5) ◽  
pp. F509-F516
Author(s):  
U. Trohler ◽  
J. P. Bonjour ◽  
H. Fleisch
Keyword(s):  
Diurnal Fluctuation ◽  
Renal Handling ◽  
Reabsorptive Capacity ◽  
Overnight Fasting ◽  
Per Se ◽  
The Difference ◽  
Renal Tubular ◽  
Fasted Rats ◽  
Pi Deprivation

Overnight fasting significantly increases plasma inorganic phosphate ([Pi]p) in rats previously fed low Pi diet (LPD), whereas it slightly decreases [Pi]p in rats previously fed high Pi diet (HPD). We assessed the role of the kidney in these differing responses by investigating the influence of overnight fasting on renal tubular capacity to reabsorb Pi by clearance technique in conscious rats. To also evaluate the effect of Pi deprivation during overnight fasting three groups of animals were studied: fed, completely fasted, and fasted with a Pi supply in the drinking water. In intact LPD and HPD rts the tubular Pi reabsorptive capacity was not different between fed and completely fasted rats. It was, however, found to be lower in fasted but Pi-supplied than in fed animals, indicating a decrease by overnight fasting with respect to all nutrients except Pi, i.e., by fasting per se. Conversely, it was higher in the animals completely fasted than in those fasted but Pi-supplied, showing an increase by overnight Pi deprivation. These two opposite effects explain the absence of any significant influence of overnight complete fasting on tubular Pi handling. The same results were obtained in thyroparathyroidectomized rats on low Pi intake. This study shows that the kidney can adapt its transport capacity for Pi according to changes in Pi supply within 12 h. It also suggests that it may react by a decrease in reabsorption to the reduction in Pi utilization that can be expected to occur during fasting per se. Furthermore, our data explain how the kidney, by adapting its tubular Pi transport to the prior dietary intake of Pi, can account for the difference in phosphatemic response to overnight fasting and consequently in the diurnal fluctuation of [Pi]p observed between LPD and HPD animals.

Role of glucocorticoids in the maturation of renal cortical Na+-K+-ATPase during fetal life in sheep

1999 ◽  
Vol 276 (6) ◽  
pp. R1825-R1832 ◽  
Author(s):  
Jean A. Petershack ◽  
Sudhir C. Nagaraja ◽  
Edward N. Guillery
Keyword(s):  
Atpase Activity ◽  
Proximal Tubule ◽  
Salt Transport ◽  
Protein Abundance ◽  
Fetal Life ◽  
Fetal Sheep ◽  
Pump Activity ◽  
Near Term ◽  
Treatment Activity

Glucocorticoid levels increase greatly at the time of birth in humans and sheep, coinciding with an increased ability of the kidney to reabsorb sodium. Cortisol induces proximal tubule apical membrane Na+/H+exchanger maturation in near-term fetal sheep. Proximal tubule salt transport is ultimately dependent on Na+ pump activity, so we studied the effects of cortisol treatment on renal cortical Na+-K+-ATPase. We first looked at six 140 day gestation fetal sheep (term is 145) and compared their renal cortical Na+-K+-ATPase to that of six 1-day-old lambs. Na+-K+-ATPase activity increased 80% after birth. Then nine pairs of twin fetal sheep were chronically instrumented at 127 days gestation. After 72 h recovery, one twin was given a 48-h continuous intraperitoneal infusion of cortisol. Both twins were then killed, and their renal cortices were studied. Na+-K+-ATPase activity increased 122% with cortisol treatment; activity equaled that of 1-day-old lambs. Protein abundance of the α1-subunit of the Na+-K+-ATPase increased 19%; the β1-subunit increased 39% with cortisol treatment. mRNA abundance of the α1-subunit increased 58%; the β1-subunit increased 72%. These results indicate that cortisol matures Na+-K+-ATPase activity.

The role of differential phase contrast in electron microscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 176-177
Author(s):  
E.M. Waddell ◽  
J.N. Chapman ◽  
R.P. Ferrier
Keyword(s):  
Phase Contrast ◽  
Practical Method ◽  
Position Vector ◽  
Differential Phase ◽  
Pure Phase ◽  
Differential Phase Contrast ◽  
The Difference ◽  
Image Position ◽  
First Moment

Dekkers and de Lang (1977) have discussed a practical method of realising differential phase contrast in a STEM. The method involves taking the difference signal from two semi-circular detectors placed symmetrically about the optic axis and subtending the same angle (2α) at the specimen as that of the cone of illumination. Such a system, or an obvious generalisation of it, namely a quadrant detector, has the characteristic of responding to the gradient of the phase of the specimen transmittance. In this paper we shall compare the performance of this type of system with that of a first moment detector (Waddell et al.1977).For a first moment detector the response function R(k) is of the form R(k) = ck where c is a constant, k is a position vector in the detector plane and the vector nature of R(k)indicates that two signals are produced. This type of system would produce an image signal given bywhere the specimen transmittance is given by a (r) exp (iϕ (r), r is a position vector in object space, ro the position of the probe, ⊛ represents a convolution integral and it has been assumed that we have a coherent probe, with a complex disturbance of the form b(r-ro) exp (iζ (r-ro)). Thus the image signal for a pure phase object imaged in a STEM using a first moment detector is b2 ⊛ ▽ø. Note that this puts no restrictions on the magnitude of the variation of the phase function, but does assume an infinite detector.

Role of stat6 in hypercontractility of murine small intestinal smooth muscle induced by nematode infection

2001 ◽  
Vol 120 (5) ◽  
pp. A534-A534
Author(s):  
A ZHAO ◽  
D MULLOY ◽  
J URBANJR ◽  
W GAUSE ◽  
T SHEADONOHUE
Keyword(s):  
Smooth Muscle ◽  
Nematode Infection ◽  
Intestinal Smooth Muscle ◽  
Small Intestinal

On the Role of Transferrin in 67Ga Uptake by Tumor Cells

1988 ◽  
Vol 27 (04) ◽  
pp. 151-153
Author(s):  
P. Thouvenot ◽  
F. Brunotte ◽  
J. Robert ◽  
L. J. Anghileri
Keyword(s):  
Specific Binding ◽  
Subcellular Fractionation ◽  
Animal Blood ◽  
Tumor Bearing ◽  
Cell Structures ◽  
The Difference ◽  
Sarcoma Cells ◽  
In Vitro Uptake

In vitro uptake of 67Ga-citrate and 59Fe-citrate by DS sarcoma cells in the presence of tumor-bearing animal blood plasma showed a dramatic inhibition of both 67Ga and 59Fe uptakes: about ii/io of 67Ga and 1/5o of the 59Fe are taken up by the cells. Subcellular fractionation appears to indicate no specific binding to cell structures, and the difference of binding seems to be related to the transferrin chelation and transmembrane transport differences

REFLECTION COEFFICIENT OF AN ELECTROMAGNETIC WAVE IN CONDUCTIVE MEDIA

2018 ◽  
pp. 100-106
Author(s):  
M. S. Sudakova ◽  
M. L. Vladov ◽  
M. R. Sadurtdinov
Keyword(s):  
Reflection Coefficient ◽  
Ground Penetrating Radar ◽  
Electromagnetic Waves ◽  
Water Contamination ◽  
Survey Design ◽  
Direct And Inverse Problems ◽  
The Difference ◽  
Ground Penetrating ◽  
Ideal Dielectric

Within the ground penetrating radar bandwidth the medium is considered to be an ideal dielectric, which is not always true. Electromagnetic waves reflection coefficient conductivity dependence showed a significant role of the difference in conductivity in reflection strength. It was confirmed by physical modeling. Conductivity of geological media should be taken into account when solving direct and inverse problems, survey design planning, etc. Ground penetrating radar can be used to solve the problem of mapping of halocline or determine water contamination.

Speculative Realism and Science Fiction

2017 ◽  
Author(s):  
Brian Willems
Keyword(s):  
Science Fiction ◽  
Identity Formation ◽  
Cormac Mccarthy ◽  
Doris Lessing ◽  
Speculative Realism ◽  
Neil Gaiman ◽  
The World ◽  
The Difference ◽  
Quentin Meillassoux

A human-centred approach to the environment is leading to ecological collapse. One of the ways that speculative realism challenges anthropomorphism is by taking non-human things to be as valid objects of investivation as humans, allowing a more responsible and truthful view of the world to take place. Brian Willems uses a range of science fiction literature that questions anthropomorphism both to develop and challenge this philosophical position. He looks at how nonsense and sense exist together in science fiction, the way in which language is not a guarantee of personhood, the role of vision in relation to identity formation, the difference between metamorphosis and modulation, representations of non-human deaths and the function of plasticity within the Anthropocene. Willems considers the works of Cormac McCarthy, Paolo Bacigalupi, Neil Gaiman, China Miéville, Doris Lessing and Kim Stanley Robinson are considered alongside some of the main figures of speculative materialism including Graham Harman, Quentin Meillassoux and Jane Bennett.

On the Use of Quantum Thermal Bath in Unimolecular Fragmentation Simulations

2019 ◽  
Author(s):  
Riccardo Spezia ◽  
Hichem Dammak
Keyword(s):  
Degrees Of Freedom ◽  
Molecular Simulations ◽  
Zero Point ◽  
Thermal Bath ◽  
Unimolecular Dissociation ◽  
Point Energy ◽  
Rotational Degrees Of Freedom ◽  
The Difference ◽  
Nuclear Effects

<div> <div> <div> <p>In the present work we have investigated the possibility of using the Quantum Thermal Bath (QTB) method in molecular simulations of unimolecular dissociation processes. Notably, QTB is aimed in introducing quantum nuclear effects with a com- putational time which is basically the same as in newtonian simulations. At this end we have considered the model fragmentation of CH4 for which an analytical function is present in the literature. Moreover, based on the same model a microcanonical algorithm which monitor zero-point energy of products, and eventually modifies tra- jectories, was recently proposed. We have thus compared classical and quantum rate constant with these different models. QTB seems to correctly reproduce some quantum features, in particular the difference between classical and quantum activation energies, making it a promising method to study unimolecular fragmentation of much complex systems with molecular simulations. The role of QTB thermostat on rotational degrees of freedom is also analyzed and discussed. </p> </div> </div> </div>

«Имперский синдром»: концепция османского халифата на Ближнем Востоке и в Южной Азии (первая четверть XX в.)

2019 ◽  
Author(s):  
S.A. Kirillina ◽  
A.L. Safronova ◽  
V.V. Orlov
Keyword(s):  
Middle East ◽  
South Asia ◽  
South Asian ◽  
Political Role ◽  
The Social ◽  
The Difference ◽  
Aspect Interaction ◽  
Muhammad Rashid Rida ◽  
Political Actions

Аннотация В статье изучены общие и специфические черты идейных воззрений, пропагандистской риторики и политических действий представителей халифатистского движения на Ближнем Востоке и в Южной Азии. В ретроспективном ключе прослеживается эволюция представлений о сущности и необходимости возрождения института халифата в трудах исламских идеологов, реформаторов и политиков Джамал ад-Дина ал-Афгани, Абд ар-Рахмана ал-Кавакиби, Мухаммада Рашида Риды, Абул Калама Азада. Внимание авторов сосредоточено на общественно-политических дискуссиях 2030-х годов XX столетия, а также на повестке дня халифатистских конгрессов и конференций этого периода. На них вырабатывались первые представления современников о пост-османском формате мусульманского единства и идейно-политической роли будущего халифата. Авторы демонстрируют различие между моделями реакции мусульман Ближнего Востока и Южной Азии на упразднение османского халифата республиканским руководством Турции. Установлена многоаспектная взаимосвязь между халифатистскими ценностями, проосманскими настроениями и формами самоотождествления, которые сложились в арабских и южноазиатских обществах. Отдельно намечено соотношение между подъемом халифатистских настроений и радикализацией антиколониальных действий мусульман Индостана.Abstract The article deals with analysis of common and specific features of ideas, propaganda, rhetoric and political actions taken by representatives of the movement for defense of the Caliphate in the Middle East and South Asia. The retrospection showing the transformation of conception of the Caliphate and the necessity of its revival in the works of eminent ideologists and politicians of the Muslim world Jamal al-Din al-Afghani, Abd al-Rahman al-Kawakibi, Muhammad Rashid Rida and Abul Kalam Azad, is also given in the article. The authors also focus on the social and political discussions of the 1920s 1930s, as well as on the agenda of Caliphatist congresses and conferences of this period. They helped to elaborate the early representations of post-Ottoman pattern of the Muslim unity and the ideological and political role of the future Caliphate. The authors demonstrate the difference between the forms of reaction of Muslims in the Middle East and South Asia to the repudiation of the Caliphate by the Republican leaders of Turkey. The article establishes a multi-aspect interaction between the Caliphatist values and forms of self-identification, emerged in Arab and South Asian societies. The correlation between the rise of Caliphatist attitudes and radicalization of anti-colonial actions of South Asian Muslims is also outlined.

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