scholarly journals Modulation of vH+-ATPase is part of the functional adaptation of sheep rumen epithelium to high-energy diet

2012 ◽  
Vol 303 (9) ◽  
pp. R909-R920 ◽  
Author(s):  
Judith Kuzinski ◽  
Rudolf Zitnan ◽  
Elke Albrecht ◽  
Torsten Viergutz ◽  
Monika Schweigel-Röntgen

Ruminal vacuolar H+-ATPase (vH+-ATPase) activity is regulated by metabolic signals. Thus, we tested whether its localization, expression, and activity were changed by different feeding. Young male sheep ( n = 12) were either fed hay ad libitum (h) or hay ad libitum plus additional concentrate (h/c) for 2 wk. The vH+-ATPase B subunit signal was predominantly found in the cell membrane and cytosol of rumen epithelial cells (REC) with basal/parabasal phenotype. The elevated number (threefold) of these cells in rumen mucosa of h/c-fed sheep reflects a high proliferative capacity and, explains the 2.3-fold increase of the total number of vH+-ATPase-expressing REC. However, in accordance with a 58% reduction of the vH+-ATPase B subunit mRNA expression in h/c-fed sheep, its protein amount per single REC was decreased. Using the fluorescent probe BCECF and selective inhibitors (foliomycin, amiloride), the contribution of vH+-ATPase and Na+/H+ exchanger to intracellular pH (pHi) regulation was investigated. REC isolated from h/c-fed sheep keep their pHi at a significantly higher level (6.91 ± 0.03 vs. 6.74 ± 0.05 in h-fed sheep). Foliomycin or amiloride decreased pHi by 0.16 ± 0.02 and 0.57 ± 0.04 pH units when applied to REC from h-fed sheep, but the effects were markedly reduced (−88 and −33%) after concentrate feeding. Nevertheless, we found that REC proliferation rate and [cAMP]i were reduced after foliomycin-induced vH+-ATPase inhibition. Our results provide the first evidence for a role of vH+-ATPase in regulation of REC proliferation, most probably by linking metabolically induced pHi changes to signaling pathways regulating this process.

2011 ◽  
Vol 54 (3) ◽  
pp. 280-286 ◽  
Author(s):  
J. Kuzinski ◽  
M. Röntgen

Abstract. In this study the protein and mRNA expression of Monocarboxylate transporter 1 (MCT1) was evaluated in rumen epithelial cells (REC) obtained from sheep fed hay ad libitum (control, h diet, n=4) or a mixed hay/concentrate diet (h/c diet, n=4) for two weeks. REC were isolated via fractionated trypsination and three groups consisting of fractions 3 to 5=G1, fractions 6 to 8=G2, and fractions 9 and 10=G3 were formed. Using an anti-basal cytokeratin antibody and flow cytometric analysis, the proportion of REC originating from the stratum basale (SB) was determined for each group. In addition, MCT1 mRNA and protein expression was determined by qRT-PCR and Western blot, respectively. Feeding the h/c diet led to a 299±93 % elevation of the number of SB cells known to express the MCT1 protein. This is accompanied by an increased MCT1 mRNA (1.8 to 2.2-fold) and protein (1.3-fold) expression. Thus, an increased number of MCT1 expressing cells and upregulation of ruminal MCT1 protein seem to be components of rumen epithelium functional adaptation to high energy diet.


2002 ◽  
Vol 174 (1) ◽  
pp. 71-83 ◽  
Author(s):  
HA Kenny ◽  
DJ Bernard ◽  
TH Horton ◽  
TK Woodruff

Follicle-stimulating hormone (FSH) stimulates ovarian follicle development and the production of protein hormones including inhibin A and inhibin B. The inhibins are dimeric proteins (alpha-beta(A) or alpha-beta(B)) secreted by growing follicles that suppress FSH in a classical endocrine negative feedback loop. Siberian hamsters, Phodopus sungorus, exhibit seasonal variation in FSH levels. Given the role of inhibin in FSH regulation, we hypothesized that ovarian inhibin expression differs between animals reared in long (16 h light:8 h darkness) and short (6 h light:18 h darkness) photoperiods. To examine inhibin expression in animals housed under long or short photoperiods, hamster inhibin alpha-, beta(A)-, and beta(B)-subunits were cloned and used to detect and localize inhibin subunit mRNA in developing follicles. Ovarian inhibin alpha-subunit mRNA levels were significantly higher in long day-exposed (LD) than in short day-exposed (SD) hamsters. In addition, dimeric inhibin, as well as inhibin alpha-, beta(A)-, and beta(B)-subunit protein levels were higher in the LD than in the SD hamster ovaries.


1992 ◽  
Vol 67 (01) ◽  
pp. 111-116 ◽  
Author(s):  
Marcel Levi ◽  
Jan Paul de Boer ◽  
Dorina Roem ◽  
Jan Wouter ten Cate ◽  
C Erik Hack

SummaryInfusion of desamino-d-arginine vasopressin (DDAVP) results in an increase in plasma plasminogen activator activity. Whether this increase results in the generation of plasmin in vivo has never been established.A novel sensitive radioimmunoassay (RIA) for the measurement of the complex between plasmin and its main inhibitor α2 antiplasmin (PAP complex) was developed using monoclonal antibodies preferentially reacting with complexed and inactivated α2-antiplasmin and monoclonal antibodies against plasmin. The assay was validated in healthy volunteers and in patients with an activated fibrinolytic system.Infusion of DDAVP in a randomized placebo controlled crossover study resulted in all volunteers in a 6.6-fold increase in PAP complex, which was maximal between 15 and 30 min after the start of the infusion. Hereafter, plasma levels of PAP complex decreased with an apparent half-life of disappearance of about 120 min. Infusion of DDAVP did not induce generation of thrombin, as measured by plasma levels of prothrombin fragment F1+2 and thrombin-antithrombin III (TAT) complex.We conclude that the increase in plasminogen activator activity upon the infusion of DDAVP results in the in vivo generation of plasmin, in the absence of coagulation activation. Studying the DDAVP induced increase in PAP complex of patients with thromboembolic disease and a defective plasminogen activator response upon DDAVP may provide more insight into the role of the fibrinolytic system in the pathogenesis of thrombosis.


Author(s):  
Richard Healey

The metaphor that fundamental physics is concerned to say what the natural world is like at the deepest level may be cashed out in terms of entities, properties, or laws. The role of quantum field theories in the Standard Model of high-energy physics suggests that fundamental entities, properties, and laws are to be sought in these theories. But the contextual ontology proposed in Chapter 12 would support no unified compositional structure for the world; a quantum state assignment specifies no physical property distribution sufficient even to determine all physical facts; and quantum theory posits no fundamental laws of time evolution, whether deterministic or stochastic. Quantum theory has made a revolutionary contribution to fundamental physics because its principles have permitted tremendous unification of science through the successful application of models constructed in conformity to them: but these models do not say what the world is like at the deepest level.


Author(s):  
R.J. Fallon ◽  
J.R. Twigge

The primary aim of the calf rearer is to ensure a successful transition from non ruminant to ruminant status while achieving rapid growth and an early intake of solid food. Newbold, Blake and Hagges (1991), found that increasing the concentration of ME in either the starter or milk replacer will not promote more rapid growth, but will simply reduce the rate of starter consumption. This present study investigated the extent to which the energy density of a calf starter ration affected starter intake and liveweight gain in calves receiving a fixed allowance of a high energy milk replacer with ad libitum access to solid calf starter rations.


Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1083
Author(s):  
Adhirath Sikand ◽  
Malgorzata Jaszczur ◽  
Linda B. Bloom ◽  
Roger Woodgate ◽  
Michael M. Cox ◽  
...  

In the mid 1970s, Miroslav Radman and Evelyn Witkin proposed that Escherichia coli must encode a specialized error-prone DNA polymerase (pol) to account for the 100-fold increase in mutations accompanying induction of the SOS regulon. By the late 1980s, genetic studies showed that SOS mutagenesis required the presence of two “UV mutagenesis” genes, umuC and umuD, along with recA. Guided by the genetics, decades of biochemical studies have defined the predicted error-prone DNA polymerase as an activated complex of these three gene products, assembled as a mutasome, pol V Mut = UmuD’2C-RecA-ATP. Here, we explore the role of the β-sliding processivity clamp on the efficiency of pol V Mut-catalyzed DNA synthesis on undamaged DNA and during translesion DNA synthesis (TLS). Primer elongation efficiencies and TLS were strongly enhanced in the presence of β. The results suggest that β may have two stabilizing roles: its canonical role in tethering the pol at a primer-3’-terminus, and a possible second role in inhibiting pol V Mut’s ATPase to reduce the rate of mutasome-DNA dissociation. The identification of umuC, umuD, and recA homologs in numerous strains of pathogenic bacteria and plasmids will ensure the long and productive continuation of the genetic and biochemical journey initiated by Radman and Witkin.


2021 ◽  
pp. 004947552098277
Author(s):  
Madhu Kharel ◽  
Alpha Pokharel ◽  
Krishna P Sapkota ◽  
Prasant V Shahi ◽  
Pratisha Shakya ◽  
...  

Evidence-based decision-making is less common in low- and middle-income countries where the research capacity remains low. Nepal, a lower-middle-income country in Asia, is not an exception. We conducted a rapid review to identify the trend of health research in Nepal and found more than seven-fold increase in the number of published health-related articles between 2000 and 2018. The proportion of articles with Nepalese researchers as the first authors has also risen over the years, though they are still only in two-thirds of the articles in 2018.


2021 ◽  
Vol 22 (11) ◽  
pp. 5918
Author(s):  
Paweł Kordowitzki ◽  
Gabriela Sokołowska ◽  
Marta Wasielak-Politowska ◽  
Agnieszka Skowronska ◽  
Mariusz T. Skowronski

The oocyte is the major determinant of embryo developmental competence in all mammalian species. Although fundamental advances have been generated in the field of reproductive medicine and assisted reproductive technologies in the past three decades, researchers and clinicians are still trying to elucidate molecular factors and pathways, which could be pivotal for the oocyte’s developmental competence. The cell-to-cell and cell-to-matrix communications are crucial not only for oocytes but also for multicellular organisms in general. This latter mentioned communication is among others possibly due to the Connexin and Pannexin families of large-pore forming channels. Pannexins belong to a protein group of ATP-release channels, therefore of high importance for the oocyte due to its requirements of high energy supply. An increasing body of studies on Pannexins provided evidence that these channels not only play a role during physiological processes of an oocyte but also during pathological circumstances which could lead to the development of diseases or infertility. Connexins are proteins that form membrane channels and gap-junctions, and more precisely, these proteins enable the exchange of some ions and molecules, and therefore they do play a fundamental role in the communication between the oocyte and accompanying cells. Herein, the role of Pannexins and Connexins for the processes of oogenesis, folliculogenesis, oocyte maturation and fertilization will be discussed and, at the end of this review, Pannexin and Connexin related pathologies and their impact on the developmental competence of oocytes will be provided.


2021 ◽  
pp. 251660852098428
Author(s):  
Vikas Bhatia ◽  
Chirag Jain ◽  
Sucharita Ray ◽  
jay Kumar

Objective: To report a case of young male with stroke and bilateral internal carotid artery (ICA) dissection. Background: Cervical Artery Dissection in Stroke Study trial has provided some insight on management of patients with ICA dissection. However, there is a need to modify the management strategies as per specific clinical scenario. Design/Methods: Case report and literature review. Results: A 45-year-old male presented with 1 month old history of acute onset numbness of right half of the body with slurring of speech. Computed tomography angiography showed complete occlusion of left cervical ICA just beyond origin with presence of fusiform dilatation and spiral flap in right extracranial cervical ICA. The patient was started on antiplatelets and taken for endovascular procedure using 2-mesh-based carotid stents. Patient was discharged after 3 days on antiplatelet therapy. At 1-year follow-up, there were no fresh symptoms. Conclusion: This case emphasizes the role of successful endovascular management of carotid dissection in a young male. These clinical situations may not be fully represented in trials, and a case-based approach is required.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 977.1-977
Author(s):  
A. Potapova ◽  
O. Egorova ◽  
O. Alekseeva ◽  
A. Volkov ◽  
S. Radenska-Lopovok

Background:Ultrasound (US) is a non-invasive and safe imaging method that allows in vivo differentiation of the morphological structures of subcutaneous fat (SCF) tissue in in normal and pathology.Objectives:Reveal features of ultrasound changes in SCF in panniculitis (Pn).Methods:57 patients (f – 45, m - 12) aged 18 - 67 years with an initial diagnosis of erythema nodosum and a disease duration of 3.6 ± 1.4 years were examined. In addition to the general clinical examination, a computed tomography of the chest organs and a pathomorphological examination of a skin biopsy from the site of the node were performed. Ultrasound was performed on a MyLabTwice apparatus (ESAOTE, Italy) using a multi-frequency linear transducer (10-18 MHz) with the PD technique, the parameters of which were adapted for recording low-speed flows (PRF 300-600 Hz, low filter, dynamic range - 20-40 dB), the presence of vascularization was assessed not only in the affected area, but also on the contralateral side using high-energy Doppler.Results:33 patients were diagnosed with septal Pn (SPn), 24 - lobular Pn (LPn). In all cases, the diagnosis was verified by histological examination. Ultrasound made it possible to assess the thickness, echoicity and vascularization of the SCF. In 35 patients, significant thickening of the SCF was revealed (as compared to the contralateral side), of which in 14 cases with SPn, in 21 - with LPn. Significant diffuse thickening of the SCF with the contralateral side was observed in 18 patients, incl. in 12 (66%) patients with LPn. Limited thickening was more typical for SPn (73%). A significant increase in the echoicity of the SCF was noted in all forms of Pn. A “lobular” echo pattern with an anechogenic environment was observed in 25 patients, of which 18 (72%) had LPn. An increase in vascularization compared to the contralateral side was recorded in 30 cases (SPn-17, LPn-13).Conclusion:The obtained preliminary results indicate the important role of ultrasound in assessing the depth and prevalence of the inflammatory process at Pn. To clarify the diagnostic value of this method, further studies are needed on a larger sample of patients.Disclosure of Interests:None declared


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