Myocardial CO2 buffering: role of transmembrane transport of H+ or HCO3-ions

1976 ◽  
Vol 230 (4) ◽  
pp. 1037-1041 ◽  
Author(s):  
DR Strome ◽  
RL Clancy ◽  
NC Gonzalez
Keyword(s):  
Small Volume ◽  
Coronary Circulation ◽  
Myocardial Cell ◽  
Ringer Solution ◽  
Red Cells ◽  
Transmembrane Transport ◽  
High Degree

Isolated rabbit hearts were perfused with rabbit red cells suspended in Ringer solution. A small volume of perfusate was recirculated for 10 min at Pco2 of 33.4 +/- 0.9 or 150.8 +/- 7.5 mmHg. Hypercapnia resulted in an increase in perfusate HCO3- concentration that was smaller than that observed when isolated perfusate was equilibrated in vitro with the same CO2 tensions (delta HCO-3e = 1.6 mM, P less than 0.01). This difference is consistent with a net movement of HCO3- into or H+ out of the mycardial cell, and cannot be accounted for by dilution of HCO3- in the myocardial interstitium. Recirculation of perfusate through the coronary circulation at normal Pco2 for two consecutive 10-min periods was not followed by changes in perfusate HCO3- concentration. A high degree of correlation (r = 0.81) was observed between intracellular HCO-3e concentration and the corresponding delta HCO-3e in individual experiments. The results suggest that transmembrane exchange of H+ or HCO3- is a buffer mechanism for CO2 in the myocardial cell.

scholarly journals MiR-26a-5p inhibits GSK3β expression and promotes cardiac hypertrophy in vitro

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10371
Author(s):  
Liqun Tang ◽  
Jianhong Xie ◽  
Xiaoqin Yu ◽  
Yangyang Zheng
Keyword(s):  
Cell Surface ◽  
Cardiac Hypertrophy ◽  
Surface Area ◽  
Myocardial Cell ◽  
Immunofluorescence Staining ◽  
Cell Surface Area ◽  
Direct Target

Background The role of miR-26a-5p expression in cardiac hypertrophy remains unclear. Herein, the effect of miR-26a-5p on cardiac hypertrophy was investigated using phenylephrine (PE)-induced cardiac hypertrophy in vitro and in a rat model of hypertension-induced hypertrophy in vivo. Methods The PE-induced cardiac hypertrophy models in vitro and vivo were established. To investigate the effect of miR-26a-5p activation on autophagy, the protein expression of autophagosome marker (LC3) and p62 was detected by western blot analysis. To explore the effect of miR-26a-5p activation on cardiac hypertrophy, the relative mRNA expression of cardiac hypertrophy related mark GSK3β was detected by qRT-PCR in vitro and vivo. In addition, immunofluorescence staining was used to detect cardiac hypertrophy related mark α-actinin. The cell surface area was measured by immunofluorescence staining. The direct target relationship between miR-26a-5p and GSK3β was confirmed by dual luciferase report. Results MiR-26a-5p was highly expressed in PE-induced cardiac hypertrophy. MiR-26a-5p promoted LC3II and decreased p62 expression in PE-induced cardiac hypertrophy in the presence or absence of lysosomal inhibitor. Furthermore, miR-26a-5p significantly inhibited GSK3β expression in vitro and in vivo. Dual luciferase report results confirmed that miR-26a-5p could directly target GSK3β. GSK3β overexpression significantly reversed the expression of cardiac hypertrophy-related markers including ANP, ACTA1 and MYH7. Immunofluorescence staining results demonstrated that miR-26a-5p promoted cardiac hypertrophy related protein α-actinin expression, and increased cell surface area in vitro and in vivo. Conclusion Our study revealed that miR-26a-5p promotes myocardial cell autophagy activation and cardiac hypertrophy by regulating GSK3β, which needs further research.

scholarly journals Allelic variation contributes to bacterial host specificity

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Min Yue ◽  
Xiangan Han ◽  
Leon De Masi ◽  
Chunhong Zhu ◽  
Xun Ma ◽  
...  
Keyword(s):  
Allelic Variation ◽  
Multinomial Logistic Regression ◽  
Gene Gain ◽  
Nucleotide Polymorphisms ◽  
Genome Wide ◽  
Serovar Typhimurium ◽  
Functional Analyses ◽  
High Degree

Abstract Understanding the molecular parameters that regulate cross-species transmission and host adaptation of potential pathogens is crucial to control emerging infectious disease. Although microbial pathotype diversity is conventionally associated with gene gain or loss, the role of pathoadaptive nonsynonymous single-nucleotide polymorphisms (nsSNPs) has not been systematically evaluated. Here, our genome-wide analysis of core genes within Salmonella enterica serovar Typhimurium genomes reveals a high degree of allelic variation in surface-exposed molecules, including adhesins that promote host colonization. Subsequent multinomial logistic regression, MultiPhen and Random Forest analyses of known/suspected adhesins from 580 independent Typhimurium isolates identifies distinct host-specific nsSNP signatures. Moreover, population and functional analyses of host-associated nsSNPs for FimH, the type 1 fimbrial adhesin, highlights the role of key allelic residues in host-specific adherence in vitro. Together, our data provide the first concrete evidence that functional differences between allelic variants of bacterial proteins likely contribute to pathoadaption to diverse hosts.

scholarly journals The Role of Red Cell Energy Metabolism in the Generation of Irreversibly Sickled Cells In Vitro

Blood ◽  
1973 ◽  
Vol 42 (6) ◽  
pp. 835-842 ◽  
Author(s):  
Michael Jensen ◽  
Stephen B. Shohet ◽  
David G. Nathan
Keyword(s):  
Energy Metabolism ◽  
Calcium Metabolism ◽  
Red Cells ◽  
Red Cell ◽  
Hemoglobin S ◽  
Cell Energy ◽  
Incubation Buffer ◽  
Membrane Defect

Abstract An acquired membrane defect is believed to be responsible for the maintenance of the sickled shape in oxygenated irreversibly sickled cells (ISC), because the hemoglobin S in these cells is not in the aggregated, "sickled" state. In the present study, it is demonstrated that the acquisition of the membrane defect in vitro depends on cellular metabolism. Only if cellular ATP is almost completely depleted while the cells are sickled, do they become unable to resume the biconcave disk shape upon reoxygenation. If calcium is omitted from the incubation buffer, ISCs are not generated despite metabolic depletion. This suggests an action of ATP mediated through calcium metabolism similar to that which prevents membrane stiffening in normal red cells. No ISCs were produced by repeated sickling and unsickling. Thus, a membrane alteration occurring as a consequence of metabolic depletion seems to be a more important factor in the generation of ISC than sickling-unsickling induced fragmentation.

scholarly journals Multi-Omics Study of The Salivary Modulation of The Rumen Microbiome

2022 ◽  
Author(s):  
Juan Manuel Palma-Hidalgo ◽  
Alejandro Belanche ◽  
Elisabeth Jiménez ◽  
A. Ignacio Martín-García ◽  
Charles J. Newbold ◽  
...  
Keyword(s):  
Rumen Fluid ◽  
Positive Control ◽  
Negative Control ◽  
Individual Variability ◽  
Rumen Bacterium ◽  
Commensal Microbiota ◽  
Rumen Microbiome ◽  
High Degree

Abstract Ruminants are able to produce large quantities of saliva which enter into the rumen. Although previous research has indicated that salivary immunoglobulins can partially modulate the rumen microbial activity, the role of the salivary components other than ions on the rumen microbial ecosystem has not been thoroughly investigated in ruminants. A total of 16 semi-continuous in vitro cultures were used to incubate rumen fluid from 4 donor goats inoculated with autoclaved saliva (AUT) as negative control, saliva from the same rumen fluid donor (OWN) as positive control, and either GOAT or SHEEP saliva as experimental interventions. Fermentation was monitored throughout the 7 days of incubation and the prokaryotic communities and metabolome were analysed at day 7 of incubation. Characterization of the salivas used prior to incubation showed a high degree of individual variability in terms of the salivary metabolites and proteins, including immunoglobulins. The prokaryotic community composition in AUT incubators was the most divergent across treatments, suggesting a modulatory effect of active salivary components, which were not affected in the other treatments (OWN, GOAT and SHEEP). The differences across treatments in microbial diversity were mostly caused by a greater abundance of Proteobacteria and Rikenellacea and lower of Prevotellaceae, a key rumen bacterium with greater abundance in GOAT and SHEEP treatments. These results suggest that specific salivary components contribute to host-associated role in selecting the rumen commensal microbiota and its activity.

Osmotic interaction of plasma proteins with interstitial macromolecules

1976 ◽  
Vol 231 (2) ◽  
pp. 638-641 ◽  
Author(s):  
CA Wiederhielm ◽  
LL Black
Keyword(s):  
Plasma Proteins ◽  
Ringer Solution ◽  
In Vivo Studies ◽  
Tissue Fluid ◽  
Oncotic Pressure ◽  
Mixed Solutions ◽  
Probable Role

The osmotic interaction of plasma proteins with collagen and hyaluronate has been evaluated by measuring the oncotic pressure of mixed solutions of varying composition. Collagen, despite its insolubility, exhibits a pronounced volume exclusion effect on plasma proteins, and the oncotic pressure of mixed solutions is considerably higher than that of the plasma protein stock solution. The volume exclusion of collagen on small molecules such as sucrose is negligible. A solution composed of 1.6% plasma proteins, 20% collagen, and .4% hyaluronate in Ringer solution, approximating the composition of the interstitium, was found to yield higher oncotic pressures than those previously reported from the interstitium. The probable role of impurities and degradation in the isolation process is discussed. Results reported earlier from in vitro and in vivo studies indicated that tissue oncotic pressures are considerably higher than generally recognized and that tissue fluid is in probable osmotic equilibrium with lymph in skin and muscle.

ROLE OF THE ERYTHROCYTES IN TRANSPORT AND METABOLISM OF 4-14C-CORTISOL

1961 ◽  
Vol 37 (3) ◽  
pp. 348-352 ◽  
Author(s):  
A. Vermeulen
Keyword(s):  
Half Life ◽  
Red Cells ◽  
Total Blood ◽  
Biological Half Life ◽  
Blood Radioactivity

ABSTRACT After infusion of 4-14C-cortisol, radioactivity associated with red cells amounts to 16 – 37 % of total blood radioactivity and its biological half life is similar to the half life of plasma radioactivity. Cortisol is not metabolized by erythrocytes in vitro. Our data suggest that the corticoids are adsorbed at the red cells surface.

In vitro Production of ‘Glomerular Red Cells’: Role of pH and Osmolality

Nephron ◽  
1990 ◽  
Vol 56 (1) ◽  
pp. 13-18 ◽  
Author(s):  
V.A. Briner ◽  
W.H. Reinhart
Keyword(s):  
Red Cells ◽  
In Vitro Production ◽  
Vitro Production

Possible role of the erythrocyte in causing prolonged cerebral vasospasm

1979 ◽  
Vol 51 (6) ◽  
pp. 773-778 ◽  
Author(s):  
Nobuyuki Ozaki ◽  
Sean Mullan
Keyword(s):  
Cerebral Vasospasm ◽  
Contractile Activity ◽  
Platelet Rich Plasma ◽  
Red Cells ◽  
Significant Activity ◽  
Sephadex Column ◽  
Content Type ◽  
Canine Basilar Artery

✓ Contractile activity of the various fractions of fresh and incubated blood was studied in vitro using the isolated canine basilar artery. Of the various fractions of fresh blood, significant contraction was induced by serum, but moderate contraction was induced by platelet-rich plasma and lysed red cells, while intact red cells and platelet-poor plasma had no significant activity. The contractions induced by serum and platelet-rich plasma were blocked by phenoxybenzamine, while those induced by lysed red cells were not. Whereas serum and platelet-rich plasma lost their contractile activity after 24 hours of incubation, lysed red cells retained activity up to 7 days after incubation. Biochemical analysis of the hemolysate by means of Sephadex column chromatography revealed that the contractile substance(s) possessed a molecular weight above 5000. These results suggest the possibility that the above substance(s) may play a role in prolonged cerebral vasospasm.

scholarly journals ACoccidioides posadasii CPS1Deletion Mutant Is Avirulent and Protects Mice from Lethal Infection

2016 ◽  
Vol 84 (10) ◽  
pp. 3007-3016 ◽  
Author(s):  
Hema P. Narra ◽  
Lisa F. Shubitz ◽  
M. Alejandra Mandel ◽  
Hien T. Trinh ◽  
Kurt Griffin ◽  
...  
Keyword(s):  
Homologous Gene ◽  
Coccidioides Posadasii ◽  
Content Type ◽  
Lethal Infection ◽  
High Doses ◽  
Regulatory Functions ◽  
High Degree ◽  
Promising Vaccine Candidate

TheCPS1gene was identified as a virulence factor in the maize pathogenCochliobolus heterostrophus. Hypothesizing that the homologous gene inCoccidioides posadasiicould be important for virulence, we created a Δcps1deletion mutant which was unable to cause disease in three strains of mice (C57BL/6, BALB/c, or the severely immunodeficient NOD-scid,γcnull[NSG]). Only a single colony was recovered from 1 of 60 C57BL/6 mice following intranasal infections of up to 4,400 spores. Following administration of very high doses (10,000 to 2.5 × 107spores) to NSG and BALB/c mice, spherules were observed in lung sections at time points from day 3 to day 10 postinfection, but nearly all appeared degraded with infrequent endosporulation. Although the role ofCPS1in virulence is not understood, phenotypic alterations and transcription differences of at least 33 genes in the Δcps1strain versusC. posadasiiis consistent with both metabolic and regulatory functions for the gene. Thein vitrophenotype of the Δcps1strain showed slower growth of mycelia with delayed and lower spore production thanC. posadasii, andin vitrospherules were smaller. Vaccination of C57BL/6 or BALB/c mice with live Δcps1spores either intranasally, intraperitoneally, or subcutaneously resulted in over 95% survival with mean residual lung fungal burdens of <1,000 CFU from an otherwise lethalC. posadasiiintranasal infection. Considering its apparently complete attenuation of virulence and the high degree of resistance toC. posadasiiinfection when used as a vaccine, the Δcps1strain is a promising vaccine candidate for preventing coccidioidomycosis in humans or other animals.

scholarly journals Role of FliC and FliD Flagellar Proteins ofClostridium difficile in Adherence and Gut Colonization

2001 ◽  
Vol 69 (12) ◽  
pp. 7937-7940 ◽  
Author(s):  
Albert Tasteyre ◽  
Marie-Claude Barc ◽  
Anne Collignon ◽  
Helene Boureau ◽  
Tuomo Karjalainen
Keyword(s):  
Cultured Cells ◽  
Adhesive Properties ◽  
Ofclostridium Difficile ◽  
Gut Colonization ◽  
Flagellar Proteins ◽  
Mouse Cecum ◽  
High Degree

ABSTRACT In vitro and in vivo adhesive properties of flagella and recombinant flagellin FliC and flagellar cap FliD proteins ofClostridium difficile were analyzed. FliC, FliD, and crude flagella adhered in vitro to axenic mouse cecal mucus. Radiolabeled cultured cells bound to a high degree to FliD and weakly to flagella deposited on a membrane. The tissue association in the mouse cecum of a nonflagellated strain was 10-fold lower than that of a flagellated strain belonging to the same serogroup, confirming the role of flagella in adherence.

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