Biliary excretion of proteins in the rat during dehydrocholate choleresis

1990 ◽  
Vol 68 (9) ◽  
pp. 1286-1291 ◽  
Author(s):  
Raúl A. Marinelli ◽  
Cristina E. Carnovale ◽  
Emilio A. Rodríguez Garay
Keyword(s):  
Acid Phosphatase ◽  
Bile Salt ◽  
Molecular Mass ◽  
Biliary Excretion ◽  
High Molecular Mass ◽  
Subsequent Increase ◽  
Microtubule Inhibitors ◽  
Protein Excretion ◽  
The Individual

Choleresis induced by dehydrocholate (DHC) stimulates the discharge into bile of lysosomes, which are implicated in the biliary excretion of proteins. Contrary to taurocholate-induced choleresis, DHC choleresis is not affected by microtubule (mt) inhibition. Therefore, the role of mt's in the biliary protein excretion during bile salt choleresis was analyzed in this study. Normal rats and rats treated with the mt poisons colchicine or vinblastine or with the acidotropic agent chloroquine (Cq) were used. The analysis of the protein component in bile was made on SDS–polyacrylamide gel, and the individual polypeptides were quantitated by densitometry. The excretion of bile polypeptides was compared with that of lysosomal acid phosphatase. Bile flow and bile salt output did not show changes on account of treatments. The biliary excretion of acid phosphatase was stimulated by DHC, and it was not affected by mt inhibitors but was markedly diminished by Cq. DHC choleresis produced different effects on the bile polypeptides. The biliary excretion of polypeptides of high molecular mass (84–140 kDa) was stimulated by DHC. Cq treatment increased their basal biliary excretions, whereas DHC-induced secretion was qualitatively and quantitatively similar to that of controls. The 69-kDa polypeptide (albumin) also increased during DHC-induced choleresis, but it showed a different excretory pattern. Cq treatment inhibited such an increase but no correlation with the excretory pattern of the lysosomal marker was found. The biliary excretion of polypeptides of low molecular mass (down to 14 kDa) suffered a transitory decrease and then a subsequent increase over basal values during the DHC choleresis. Cq treatment diminished their biliary excretions during basal and DHC-induced choleresis. Treatment with the mt inhibitors markedly diminished the biliary excretions of all polypeptides. The results indicate that DHC-induced choleresis influenced the biliary protein excretion in a way different to that induced by taurocholate. Thus, the biliary excretion of proteins that did not require lysosomes to reach the bile was stimulated, while that requiring such organelles was transiently diminished. In addition, the biliary excretion of proteins was dependent on mt's excepting those of lysosomal source.Key words: dehydrocholate choleresis, biliary proteins, microtubule inhibitors, chloroquine.

Bile protein secretion in the rat stimulated by taurocholate effect of chloroquine

1988 ◽  
Vol 66 (6) ◽  
pp. 749-753 ◽  
Author(s):  
R. A. Marinelli ◽  
C. E. Carnovale ◽  
E. A. Rodríguez Garay
Keyword(s):  
Acid Phosphatase ◽  
Molecular Mass ◽  
Protein Secretion ◽  
Biliary Excretion ◽  
Sodium Taurocholate ◽  
Protein Excretion ◽  
Chloroquine Treatment ◽  
Lysosomotropic Agent ◽  
The Individual ◽  
Bile Protein

The biliary protein excretion during sodium taurocholate induced choleresis was studied in normal rats and in rats treated with the lysosomotropic agent, chloroquine. The analysis of the protein component in bile was made on SDS–polyacrilamide gel, and the individual polypeptides were quantitated by densitometry. The excretion of bile polypeptides was compared with that of lysosomal acid phosphatase. The biliary excretion of polypeptides of molecular mass lower than and equal to 54 kDa was markedly stimulated by taurocholate-induced choleresis. Chloroquine treatment of rats diminished the biliary excretion of such polypeptides and also inhibited their excretion induced by taurocholate. The behaviour of these polypeptides was well correlated to that of the lysosomal marker. The biliary excretion of polypeptide bands of a higher molecular mass (up to 140 kDa) did not show major changes during taurocholate-induced choleresis in any of the groups. The results indicate that biliary excretion of proteins in the rat may be either stimulated by taurocholate or may be independent of the bile salt. The former requires the functional integrity of chloroquine-sensitive hepatocyte compartments, which may involve the lysosomes.

scholarly journals Effect of diosgenin on biliary cholesterol transport in the rat

1993 ◽  
Vol 291 (3) ◽  
pp. 793-798 ◽  
Author(s):  
A Thewles ◽  
R A Parslow ◽  
R Coleman
Keyword(s):  
Bile Salt ◽  
Molecular Mass ◽  
Bile Salts ◽  
Mass Fraction ◽  
Gel Permeation Chromatography ◽  
High Molecular Mass ◽  
Cholesterol Transport ◽  
Biliary Cholesterol ◽  
Lower Molecular Mass ◽  
Salt Depletion

Biliary cholesterol output in rats was stimulated over 3-fold by feeding diosgenin for 5 days, whereas biliary outputs of phospholipid and bile salts were not changed by diosgenin feeding. Isolating and perfusing the liver without bile salts resulted in a rapid and substantial decrease in biliary bile salt output; bile salt depletion abolished the diosgenin-induced increment in biliary cholesterol output, showing that the diosgenin-elevated biliary cholesterol output was bile-salt-dependent. Diosgenin treatment also produced a significant decrease in biliary alkaline phosphodiesterase I. Fresh bile obtained from control and diosgenin-fed rats was subjected to gel-permeation chromatography in order to separate different-sized biliary cholesterol carriers. Two major peaks of cholesterol were eluted, with cholesterol also being eluted between the peaks. The cholesterol peak eluted at the lower molecular mass (20-30 kDa) was observed in all bile samples. The higher-molecular-mass peak, which was eluted at the void volume, was not observed in all biles; control biles contained very little high-molecular-mass form of cholesterol, whereas biles from the diosgenin group contained up to 47% of cholesterol in the high-molecular-mass fraction. Diosgenin treatment produced a range of elevated biliary cholesterol values which positively correlated with the proportion of cholesterol contained in the high-molecular-mass fraction (r = 0.98). The results show that diosgenin induced a marked bile-salt-dependent increase in biliary cholesterol output and a shift in biliary cholesterol transport to higher-molecular-mass structures.

scholarly journals Role of DNAS1L3 in Ca2+- and Mg2+-dependent cleavage of DNA into oligonucleosomal and high molecular mass fragments

1999 ◽  
Vol 27 (9) ◽  
pp. 1999-2005 ◽  
Author(s):  
A. G. Yakovlev ◽  
G. Wang ◽  
B. A. Stoica ◽  
C. M. Simbulan-Rosenthal ◽  
M. E. Smulson ◽  
...  
Keyword(s):  
Molecular Mass ◽  
High Molecular Mass

The study of intracellular and secreted high-molecular-mass protease(s) of Trichoderma spp., and their responses to conidiation stimuli

2019 ◽  
Vol 65 (9) ◽  
pp. 653-667
Author(s):  
Matej Mat’at’a ◽  
Helena Galádová ◽  
L’udovít Varečka ◽  
Martin Šimkovič
Keyword(s):  
Molecular Mass ◽  
Botrytis Cinerea ◽  
Fusarium Culmorum ◽  
Physiological Role ◽  
High Molecular Mass ◽  
Trichoderma Spp ◽  
Direct Role ◽  
Penicillium Purpurogenum ◽  
The Media

We continued our study of high-molecular-mass proteases (HMMPs) using several strains of the genus Trichoderma, and other filamentous fungi (Botrytis cinerea, Aspergillus niger, Fusarium culmorum, and Penicillium purpurogenum). We found that five Trichoderma strains secreted HMMPs into the media after induction with bovine serum albumin. Botrytis cinerea and F. culmorum secreted proteases in the absence of inducer, while A. niger or P. purpurogenum did not secrete proteolytic activity (PA). The activity of HMMPs secreted by or intracellularly located in Trichoderma spp. represents the predominant part of cellular PA, according to zymogram patterns. This observation allowed the study of HMMPs’ physiological role(s) independent from the secretion. In studying conidiation, we found that illumination significantly stimulated PA in Trichoderma strains. In the T. atroviride IMI 206040 strain, we demonstrated that this stimulation is dependent on the BLR1 and BLR2 receptors. No stimulation of PA was observed when mechanical injury was used as an elicitor of conidiation. Compounds used as inhibitors or activators of conidiation exerted no congruent effects on both PA and conidiation. These results do not favour a direct role of HMMPs in conidiation. Probably, HMMP activity may be involved in the process of the activation of metabolism during vegetative growth, differentiation, and aging-related processes.

scholarly journals How do terrestrial plants access high molecular mass organic nitrogen, and why does it matter for soil organic matter stabilization?

2021 ◽  
Author(s):  
Bartosz Adamczyk
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Root Growth ◽  
Molecular Mass ◽  
High Molecular Mass ◽  
Organic N ◽  
Terrestrial Plants ◽  
Plant Use ◽  
Organic Matter Stabilization

AbstractAlthough there is increasing awareness of the potential role of organic N compounds (ON) in plant nutrition, its implications for soil organic matter (SOM) stabilization have hardly been discussed yet. The aim of this paper is therefore to gather the newest insights into plant use of high molecular mass organic N, its effect on root growth and anatomy, and finally, to discuss the implications of plant use of organic N for SOM stabilization. I propose that modified root growth due to the uptake of ON provides greater root and root-associated microbe input, leading to enhanced SOM stabilization. Finally, I discuss the role of the proposed framework in different ecosystems, and I encourage future studies combining plant N nutrition and SOM stabilization.

Role of high molecular mass organics in colour formation during biological treatment of pulp and paper wastewater

2007 ◽  
Vol 55 (6) ◽  
pp. 191-198 ◽  
Author(s):  
C.B. Milestone ◽  
T.R. Stuthridge ◽  
R.R. Fulthorpe
Keyword(s):  
Molecular Mass ◽  
Biological Treatment ◽  
Treatment Process ◽  
Anaerobic Bacteria ◽  
High Molecular Mass ◽  
Pulp And Paper ◽  
Wastewater Treatment Process ◽  
Organic Constituents ◽  
Paper Wastewater

This paper forms part of series of biological treatment colour behaviour studies. Surveys across a range of mills have observed colour increases in aerated stabilisation basins of 20–45%. Much of the colour formation has been demonstrated to occur in high molecular mass effluent organic constituents (HMM) present in bleach plant effluents. Removing material greater than 3,000 Da essentially eliminated the colour forming ability in both E and D stage wastewaters. We have also shown that pulp and paper sludges contain anaerobic bacteria capable of reducing humic like materials. Colour formation was correlated to the anoxic conditions and the availability of readily biodegradable organic constituents during the wastewater treatment process. Overall, these studies suggest that colour formation in pulp and paper biological treatment systems may be caused by anaerobic bacteria using HMM material from the bleaching effluents as an electron acceptor for growth. This leads to the reduction of the material, which in turn leads to non-reversible internal changes, such as intra-molecular polymerisation or formation of chromophoric functional groups.

Studies of Vegetative Plant Tissue Compatibility/Incompatibility: The Role of Acid Phosphatase in Lethal Cell Senescence in an Incompatible Heterograft

1980 ◽  
Vol 38 ◽  
pp. 530-531
Author(s):  
Randy Moore
Keyword(s):  
Acid Phosphatase ◽  
Thick Layer ◽  
Cell Necrosis ◽  
Enzyme Localization ◽  
Vegetative Plant ◽  
Cell Autolysis ◽  
Graft Interface ◽  
System 1 ◽  
Thin Fibril

Previous work has indicated that the graft incompatihility between Sedrmi telephoides and Solanum pennellil involves cell necrosis that results In a thick layer of collapsed cells at the graft Interface. This necrotic layer insulates the stock from the scion, which results in abscission of the Sedum scion after 4-6 weeks due to desiccation and starvation. Thus, cell autolysis (which is restricted to Sedum) characterizes the Incompatibility response in this system (1). In order to elucidate the events that lead to cell autolysis, and thus better understand the cellular site and mode of action of cellular incompatibility, the appearance and fate of the hydrolytlc enzyme acid phosphatase (AP) was followed in both the compatible Sedum autograft and the incompatible Sedum/Solanum heterograft. Acid phosphatase was localized by a modified Gomori-type reaction; positive (i.e., including NaF inhibitor) and negative (lacking substrate) controls showed no enzymatic precipitate. Following an initial association with the endoplasmic reticulum (ER) and dictyosomes at 6-10 hours after grafting, AP activity in the compatible Sedum autograft is associated primarily with the plasmalemma (Fig. 1). By 18-24 hours after grafting, the AP activity is restricted to the tono-plast and vacuole (Fig. 2). This strict compartmentation and absence of enzyme from the cytosol is maintained throughout the development of the compatible graft. While AP activity in the incompatible Sedum/Solanum heterograft is Initially similar to the compatible Sedum autograft (i.e., initially found on the ER and dictyosomes), there is a marked difference in enzyme localization in the two graft partners as the incompatibility response develops. As in the compatible autograft, Solanum cells at the graft interface show an Increase in AP activity that Is restricted to the vacuole and tonoplast, with little or no enzyme activity in the cytosol (Fig. 3). In comparable Sedum cells, however, there is a dramatic Increase In AP activity in the cytosol (Fig. h); this cytosollc AP activity is associated with thin fibril-like structures (Fig. 5) measuring approximately 60 A in diameter. This high cytoplasmic AP activity In Sedum cells results in cell autolysis, death, and eventual cell collapse to form the characteristic necrotic layer separating the two graft partners.

School Success and School Engagement of Immigrant Children and Adolescents

2013 ◽  
Vol 18 (2) ◽  
pp. 126-135 ◽  
Author(s):  
Frosso Motti-Stefanidi ◽  
Ann S. Masten
Keyword(s):  
Academic Achievement ◽  
Academic Success ◽  
Children And Adolescents ◽  
School Engagement ◽  
School Success ◽  
Immigrant Children ◽  
Integrative Model ◽  
High Stakes ◽  
The Individual

Academic achievement in immigrant children and adolescents is an indicator of current and future adaptive success. Since the future of immigrant youths is inextricably linked to that of the receiving society, the success of their trajectory through school becomes a high stakes issue both for the individual and society. The present article focuses on school success in immigrant children and adolescents, and the role of school engagement in accounting for individual and group differences in academic achievement from the perspective of a multilevel integrative model of immigrant youths’ adaptation ( Motti-Stefanidi, Berry, Chryssochoou, Sam, & Phinney, 2012 ). Drawing on this conceptual framework, school success is examined in developmental and acculturative context, taking into account multiple levels of analysis. Findings suggest that for both immigrant and nonimmigrant youths the relationship between school engagement and school success is bidirectional, each influencing over time the other. Evidence regarding potential moderating and mediating roles of school engagement for the academic success of immigrant youths also is evaluated.

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