Oxidative metabolic activity of boar spermatozoa: a system for assessing anti-glycolytic activity of potential inhibitors in vitro

1989 ◽  
Vol 1 (4) ◽  
pp. 357 ◽  
Author(s):  
AR Jones ◽  
LA Chantrill
Keyword(s):  
Metabolic Activity ◽  
Oxidative Metabolism ◽  
Model System ◽  
High Rate ◽  
Chemical Agents ◽  
Glycolytic Activity ◽  
Metabolic Capability ◽  
Potential Inhibitors ◽  
Boar Spermatozoa

The oxidative metabolic capability of mature boar spermatozoa has been determined in vitro. The high rate of oxidation of fructose, glucose, glycerol, glycerol-3-phosphate and lactate to CO2 and the optimization of incubation conditions indicates that these cells could constitute a model system for investigating the anti-glycolytic activity of potential male anti-fertility agents. The effects of several chemical agents on the oxidative metabolism of boar spermatozoa are reported.

Is the function of the renal papilla coupled exclusively to an anaerobic pattern of metabolism?

1979 ◽  
Vol 236 (5) ◽  
pp. F423-F433 ◽  
Author(s):  
J. J. Cohen
Keyword(s):  
Oxidative Metabolism ◽  
Aerobic Glycolysis ◽  
Collecting Duct ◽  
High Rate ◽  
O2 Uptake ◽  
Duct Cells ◽  
Collecting Duct Cells ◽  
Mitochondrial Oxidative Metabolism

It is widely accepted that in vivo the function of the papilla of the mammalian kidney is supported primarily by anaerobic metabolism. As a result, the major source of energy for support of function in the papilla is considered to be derived from glycolysis. This orientation originates from two concepts: 1) that in vivo the gaseous environment of the papilla has such a low PO2 that O2 availability limits O2 consumption, and 2) that papillary tissue has a high rate of glycolysis when compared with either cortical tissue or extrarenal tissues. It has also been tacitly assumed that papillary tissue has a "low" O2 uptake. Review of the measurements of PO2 of papillary tissue and of urine PO2 indicates that the PO2 of papillary tissue should not limit its aerobic mitochondrial oxidative metabolism. While the rate of aerobic glycolysis in papillary tissue is high, simultaneously papillary tissue has a rate of O2 uptake similar to that of liver and higher than that of muscle. The major (two-thirds) source of energy for papillary tissue in vitro is from O2 uptake. That papillary tissue is not exclusively dependent on glucose for its energy requirements is indicated by the greater stimulation of papillary tissue QO2 by succinate than by glucose. Thus, papillary tissue has both a high aerobic mitochondrial oxidative metabolism and a high aerobic glycolytic metabolism. It is suggested that the mechanism for the high rate of aerobic glycolysis in the presence of an adequate O2 supply is due to the relatively small mass of mitochondria in papillary tissue in relation to the amount of work done by the tissue. As a result of the limited rate of ATP production by the mitochondrial electron transport chain, the phosphorylation state ([ATP]/[ADP][Pi]) is reduced and the cytoplasmic redox state ([NAD+]/[NADH]) of the papillary collecting duct cells also becomes more reduced; changes in both ratios enhance the rate of glycolysis. This limited metabolic capacity of the collecting duct cells may permit an excess volume of solute and water to be excreted during volume expansion diuresis. The metabolic characteristics of the papilla, when compared to cortex, also provide a basis for the observed differences in substrate selectivity of cortex and medulla with respect to utilization of glucose and lactate. The experimental approaches that may provide information bearing on the suggested mechanisms for regulation of papillary metabolism in relation to tubular work functions are indicated.

scholarly journals Inhibition of Fructolysis in Boar Spermatozoa by the Male Antifertility Agent (S)-a-Chlorohydrin

1982 ◽  
Vol 35 (6) ◽  
pp. 595 ◽  
Author(s):  
Denise Stevenson ◽  
A RJones
Keyword(s):  
Oxidative Metabolism ◽  
Inhibitory Activity ◽  
Energy Charge ◽  
Substrate Level Phosphorylation ◽  
Charge Potential ◽  
Substrate Level ◽  
Glyceraldehydephosphate Dehydrogenase ◽  
Fructose 1,6 Bisphosphate ◽  
Boar Spermatozoa

The (S)-isomer of the male antifertility agent IX-chlorohydrin strongly inhibited the oxidative metabolism of fructose by boar spermatozoa in vitro. The result of this action, which has been deduced to be an inhibition of glyceraldehydephosphate dehydrogenase, caused an accumulation of fructose- 1,6-bisphosphate and the triosephosphates, and a decrease in substrate-level phosphorylation with a concomitant lowering of the energy charge potential of the spermatozoa. The (R)-isomer of IX-chlorohydrin had no inhibitory activity on fructolysis.

Metabolic activity of hypotonically treated mature boar spermatozoa

1997 ◽  
Vol 9 (6) ◽  
pp. 583 ◽  
Author(s):  
A. R. Jones
Keyword(s):  
Oxygen Uptake ◽  
Metabolic Activity ◽  
Phosphate Buffer ◽  
Cytoplasmic Membrane ◽  
Mitochondrial Activity ◽  
Glycolytic Activity ◽  
Boar Sperm ◽  
Uptake Studies ◽  
Boar Spermatozoa

Treatment of washed boar sperm with hypotonic phosphate buffer removed the acrosome, disrupted the cytoplasmic membrane and almost completely separated the heads from the mid piece-tail segment. As assessed by oxygen uptake studies and their ability to oxidize14C-labelled substrates to 14CO2, hypotonically-treated cells exhibit low glycolytic activity yet mitochondrial activity remains high. Both lactate and glycerol 3-phosphate underwent oxidation and these substrates continued to be metabolized by this preparation which had been stored for up to 10 days at 4°C. Such preparations may be of assistance in the investigation of the biochemistry of boar sperm mitochondria.

The anti-glycolytic activity of 3-bromopyruvate on mature boar spermatozoa in vitro

Contraception ◽  
1995 ◽  
Vol 52 (5) ◽  
pp. 317-320 ◽  
Author(s):  
A.R. Jones ◽  
L. Gillan ◽  
D. Milmlow
Keyword(s):  
Glycolytic Activity ◽  
Boar Spermatozoa

Inhibition of glycolysis in boar spermatozoa by alpha-chlorohydrin phosphate appears to be mediated by phosphatase activity

1995 ◽  
Vol 7 (5) ◽  
pp. 1089 ◽  
Author(s):  
AR Jones ◽  
LM Porter
Keyword(s):  
Phosphatase Activity ◽  
Triosephosphate Isomerase ◽  
Specific Inhibitor ◽  
Glycolytic Activity ◽  
Boar Sperm ◽  
Inhibition Of Glycolysis ◽  
Boar Spermatozoa

(R,S)-alpha-chlorohydrin-1-phosphate, previously shown to have no anti-glycolytic activity on mature boar sperm in vitro, is a substrate for acid and/or neutral phosphatase(s) that are associated with washed sperm. The high phosphatase activity hydrolyses the ester to alpha-chlorohydrin which undergoes oxidation to (S)-3-chlorolactaldehyde, a specific inhibitor of sperm glyceraldehyde-3-phosphate dehydrogenase and triosephosphate isomerase, thereby exhibiting an anti-glycolytic action.

Docking Simulations Exhibit Bortezomib and other Boron-containing Peptidomimetics as Potential Inhibitors of SARS-CoV-2 Main Protease

2020 ◽  
Vol 14 ◽  
Author(s):  
Iván R Vega-Valdez ◽  
Melvin N Rosalez ◽  
José M Santiago-Quintana ◽  
Eunice D Farfán-García ◽  
Marvin A Soriano-Ursúa
Keyword(s):  
Crystal Structure ◽  
In Vitro Assays ◽  
Docking Simulations ◽  
Chemical Agents ◽  
Main Protease ◽  
Drug Designing ◽  
Potential Inhibitors ◽  
Key Residues

Background:: Treatment of the COVID19 pandemic requires drug development. Boron-containing compounds are attractive chemical agents, some of them act as proteases inhibitors. Objective:: The present study explores the role of boronic moieties in molecules interacting on the binding site of the SARS-CoV-2 main protease. Methods:: Conventional docking procedure was applied by assaying boron-free and boron-containing compounds on the recently reported crystal structure of SARS-CoV-2 main protease (PDB code: 6LU7). The set of 150 ligands includes bortezomib and inhibitors of coronavirus proteases. Results:: Most of the tested compounds share contact with key residues and poses on the cleavage pocket. Those compounds with a boron atom in its structure were often estimated with higher affinity than boron-free analogues. Conclusion:: Interactions and the affinity of boron-containing peptidomimetics strongly suggest boron-moieties increases affinity on the main protease, as it should be tested by in vitro assays. A Bis-boron-containing compound previously tested as active on SARS-virus protease and bortezomib were identified as potent ligands. These advances may be relevant for drug designing, in addition as to the suggestion of testing available boron-containing drugs in patients with COVID19 infection.

Glycolytic and oxidative metabolism in primary renal proximal tubule cultures

1989 ◽  
Vol 257 (2) ◽  
pp. C333-C340 ◽  
Author(s):  
K. G. Dickman ◽  
L. J. Mandel
Keyword(s):  
Proximal Tubule ◽  
Oxidative Metabolism ◽  
Cultured Cells ◽  
Lactate Production ◽  
Culture Conditions ◽  
Renal Proximal Tubule ◽  
Glycolytic Activity ◽  
Metabolic Properties ◽  
Primary Rabbit

Cultured cells often exhibit alterations in energy metabolism (increased glycolytic activity and decreased oxidative metabolism) during adaptation to the culture environment. The role of hypoxia as a mediator of these effects was examined by comparison of metabolism in primary rabbit renal proximal tubule (RPT) cultures maintained in stationary culture dishes (DISH), shaking Erlenmeyer flasks (SHAKE), and DISH cultures transferred back to SHAKE conditions (RESHAKE). Both oxidative metabolism and transport capacity were fully preserved in SHAKE cultures over a 24-h period. In contrast, within 6 h, DISH cultures exhibited a continuous decline in transport-dependent and -independent oxygen consumption, respiratory capacity, and ATP and K+ contents. The loss of oxidative metabolism in DISH cultures was accompanied by stimulation of lactate production, detectable within 1 h after plating. Comparison of metabolic properties of DISH cultures to those of RPT exposed to graded levels of hypoxia suggested that medium oxygen tensions may be as low as 1-3% in DISH cultures. RESHAKE cultures exhibited metabolic properties comparable to those of SHAKE cultures, indicating reversibility of DISH culture metabolism on reoxygenation. We concluded that DISH cultures rapidly become hypoxic as a consequence of static culture conditions. Shaking suspension cultures may provide a more metabolically appropriate model for long-term in vitro studies.

scholarly journals Nanostructured surface bioactive composite scaffold for filling of bone defects

2020 ◽  
Vol 10 (2) ◽  
pp. 5038-5047
Keyword(s):  
Metabolic Activity ◽  
Bone Cells ◽  
Composite Scaffold ◽  
Osteogenic Sarcoma ◽  
Bone Cell ◽  
High Rate ◽  
Human Mscs ◽  
X Ray

The aim of this study was to investigate the chemical and physical surface properties of a hybrid nano-hydroxyapatite/collagen/polycaprolactone (nHA/Coll/PCL) material, and to test its in vitro biocompatibility and in vivo osteointegration. Mineralized collagen fibers with nHA were admixed with PCL at a weight proportion of 50:50. The material was characterized by transmission X-ray diffraction (XRD), electron microscopy (TEM), atomic force microscopy (AFM), force spectroscopy, X-ray Photoemission Spectroscopy (XPS), and biocompatibility testing using human mesenchymal stem cells (MSCs), and Hepatocyte carcinoma (HePG2) and primary osteogenic sarcoma (SAOS-2) cells as complementary tests. In addition, the ability of this material to fill three-wall bony defects was tested in the mandible of a sheep. The material had confirmed the relative low crystallinity of the HA having a nano-sized dimension, which was composed of only oxygen, carbon, calcium and phosphorus, without no residual cytotoxic element. Human MSCs on the surface scaffold showed high metabolic activity and a high rate of viability. Biocompatibility complementary testing using HePG2 and SAOS-2 cells showed good metabolic activity, and the lactate dehydrogenase assay using HePG2 cells demonstrated no significant cytotoxicity. Histological analysis of the in-vivo experimentation showed osteointegration of the material and the absence of inflammatory cells at the bone–scaffold interface. Some areas showed bone-cell seeding and isolated agglomerates of bone cells were evident in the inner scaffold.

Mechanisms involved in effects of antimicrobial peptides, bactenectins ChBac3.4, ChBac5, and mini-ChBac7.5Nb, on bacterial cells

2017 ◽  
pp. 43-50
Author(s):  
О.В. Шамова ◽  
М.С. Жаркова ◽  
П.М. Копейкин ◽  
Д.С. Орлов ◽  
Е.А. Корнева
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Innate Immunity ◽  
Infectious Diseases ◽  
Metabolic Activity ◽  
Capra Hircus ◽  
Bacterial Cells ◽  
Antibiotic Resistant ◽  
Resistant Strains

Антимикробные пептиды (АМП) системы врожденного иммунитета - соединения, играющие важную роль в патогенезе инфекционных заболеваний, так как обладают свойством инактивировать широкий спектр патогенных бактерий, обеспечивая противомикробную защиту живых организмов. В настоящее время АМП рассматриваются как потенциальные соединения-корректоры инфекционной патологии, вызываемой антибиотикорезистентными бактериями (АБР). Цель данной работы состояла в изученим механизмов антибактериального действия трех пептидов, принадлежащих к семейству бактенецинов - ChBac3.4, ChBac5 и mini-ChBac7.5Nb. Эти химически синтезированные пептиды являются аналогами природных пролин-богатых АМП, обнаруженных в лейкоцитах домашней козы Capra hircus и проявляющих высокую антимикробную активность, в том числе и в отношении грамотрицательных АБР. Методы. Минимальные ингибирующие и минимальные бактерицидные концентрации пептидов (МИК и МБК) определяли методом серийных разведений в жидкой питательной среде с последующим высевом на плотную питательную среду. Эффекты пептидов на проницаемость цитоплазматической мембраны бактерий для хромогенного маркера исследовали с использованием генетически модифицированного штамма Escherichia coli ML35p. Действие бактенецинов на метаболическую активность бактерий изучали с применением маркера резазурина. Результаты. Показано, что все исследованные пептиды проявляют высокую антимикробную активность в отношении Escherichia coli ML35p и антибиотикоустойчивых штаммов Escherichia coli ESBL и Acinetobacter baumannii in vitro, но их действие на бактериальные клетки разное. Использован комплекс методик, позволяющих наблюдать в режиме реального времени динамику действия бактенецинов в различных концентрациях (включая их МИК и МБК) на барьерную функцию цитоплазматической мембраны и на интенсивность метаболизма бактериальных клеток, что дало возможность выявить различия в характере воздействия бактенецинов, отличающихся по структуре молекулы, на исследуемые микроорганизмы. Установлено, что действие каждого из трех исследованных бактенецинов в бактерицидных концентрациях отличается по эффективности нарушения целостности бактериальных мембран и в скорости подавления метаболизма клеток. Заключение. Полученная информация дополнит существующие фундаментальные представления о механизмах действия пролин-богатых пептидов врожденного иммунитета, а также послужит основой для биотехнологических исследований, направленных на разработку на базе этих соединений новых антибиотических препаратов для коррекции инфекционных заболеваний, вызываемых АБР и являющимися причинами тяжелых внутрибольничных инфекций. Antimicrobial peptides (AMPs) of the innate immunity are compounds that play an important role in pathogenesis of infectious diseases due to their ability to inactivate a broad array of pathogenic bacteria, thereby providing anti-microbial host defense. AMPs are currently considered promising compounds for treatment of infectious diseases caused by antibiotic-resistant bacteria. The aim of this study was to investigate molecular mechanisms of the antibacterial action of three peptides from the bactenecin family, ChBac3.4, ChBac5, and mini-ChBac7.5Nb. These chemically synthesized peptides are analogues of natural proline-rich AMPs previously discovered by the authors of the present study in leukocytes of the domestic goat, Capra hircus. These peptides exhibit a high antimicrobial activity, in particular, against antibiotic-resistant gram-negative bacteria. Methods. Minimum inhibitory and minimum bactericidal concentrations of the peptides (MIC and MBC) were determined using the broth microdilution assay followed by subculturing on agar plates. Effects of the AMPs on bacterial cytoplasmic membrane permeability for a chromogenic marker were explored using a genetically modified strain, Escherichia coli ML35p. The effect of bactenecins on bacterial metabolic activity was studied using a resazurin marker. Results. All the studied peptides showed a high in vitro antimicrobial activity against Escherichia coli ML35p and antibiotic-resistant strains, Escherichia coli ESBL and Acinetobacter baumannii, but differed in features of their action on bacterial cells. The used combination of techniques allowed the real-time monitoring of effects of bactenecin at different concentrations (including their MIC and MBC) on the cell membrane barrier function and metabolic activity of bacteria. The differences in effects of these three structurally different bactenecins on the studied microorganisms implied that these peptides at bactericidal concentrations differed in their capability for disintegrating bacterial cell membranes and rate of inhibiting bacterial metabolism. Conclusion. The obtained information will supplement the existing basic concepts on mechanisms involved in effects of proline-rich peptides of the innate immunity. This information will also stimulate biotechnological research aimed at development of new antibiotics for treatment of infectious diseases, such as severe in-hospital infections, caused by antibiotic-resistant strains.

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