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.

Inhibition of glyceraldehyde 3-phosphate dehydrogenase in boar spermatozoa by bromohydroxypropanone

1995 ◽  
Vol 7 (1) ◽  
pp. 107 ◽  
Author(s):  
LM Porter ◽  
AR Jones
Keyword(s):  
Carbonyl Compound ◽  
Energy Charge ◽  
Mature Sperm ◽  
Dihydroxyacetone Phosphate ◽  
Epididymal Sperm ◽  
Charge Potential ◽  
Fructose 1,6 Bisphosphate ◽  
Boar Spermatozoa

In the presence of 3-bromo-1-hydroxypropanone (BOP), cauda epididymal sperm obtained from mature boars produced a carbonyl compound which is assumed to be (S)-3-bromolactaldehyde. Glyceraldehyde 3-phosphate dehydrogenase was rapidly inhibited which resulted in the accumulation of dihydroxyacetone phosphate and fructose-1,6-bisphosphate, and no accumulation of lactate when fructose was the substrate. The energy charge potential of the cells declined in the presence of BOP when either fructose or glycerol were substrates. It is suggested that BOP is transformed into (S)-3-bromolactaldehyde, which is the actual inhibitor of glyceraldehyde 3-phosphate dehydrogenase, thus demonstrating BOP to be the first brominated chemical to have an anti-glycolytic action on mature sperm in vitro.

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.

scholarly journals Effector-Mediated Interaction of CbbRI and CbbRII Regulators with Target Sequences in Rhodobacter capsulatus

2004 ◽  
Vol 186 (23) ◽  
pp. 8026-8035 ◽  
Author(s):  
Padungsri Dubbs ◽  
James M. Dubbs ◽  
F. Robert Tabita
Keyword(s):  
Rhodobacter Capsulatus ◽  
Energy Charge ◽  
Dnase I ◽  
Pentose Phosphate ◽  
In Vivo Studies ◽  
Mobility Shift ◽  
Fructose 1,6 Bisphosphate ◽  
Target Promoters

ABSTRACT In Rhodobacter capsulatus, genes encoding enzymes of the Calvin-Benson-Bassham reductive pentose phosphate pathway are located in the cbbI and cbbII operons. Each operon contains a divergently transcribed LysR-type transcriptional activator (CbbRI and CbbRII) that regulates the expression of its cognate cbb promoter in response to an as yet unidentified effector molecule(s). Both CbbRI and CbbRII were purified, and the ability of a variety of potential effector molecules to induce changes in their DNA binding properties at their target promoters was assessed. The responses of CbbRI and CbbRII to potential effectors were not identical. In gel mobility shift assays, the affinity of both CbbRI and CbbRII for their target promoters was enhanced in the presence of ribulose-1,5-bisphosphate (RuBP), phosphoenolpyruvate, 3-phosphoglycerate, 2-phosphoglycolate. ATP, 2-phosphoglycerate, and KH2PO4 were found to enhance only CbbRI binding, while fructose-1,6-bisphosphate enhanced the binding of only CbbRII. The DNase I footprint of CbbRI was reduced in the presence of RuBP, while reductions in the CbbRII DNase I footprint were induced by fructose-1,6-bisphosphate, 3-phosphoglycerate, and KH2PO4. The current in vitro results plus recent in vivo studies suggest that CbbR-mediated regulation of cbb transcription is controlled by multiple metabolic signals in R. capsulatus. This control reflects not only intracellular levels of Calvin-Benson-Bassham cycle metabolic intermediates but also the fixed (organic) carbon status and energy charge of the cell.

scholarly journals Energy Yield of Respiration on Chloroaromatic Compounds in Desulfitobacterium dehalogenans

2001 ◽  
Vol 67 (9) ◽  
pp. 3958-3963 ◽  
Author(s):  
Bram A. van de Pas ◽  
Stefan Jansen ◽  
Cor Dijkema ◽  
Gosse Schraa ◽  
Willem M. de Vos ◽  
...  
Keyword(s):  
Dry Weight ◽  
Growth Yields ◽  
In Vitro Assays ◽  
Energy Yield ◽  
Reductive Dehalogenase ◽  
Substrate Level Phosphorylation ◽  
Pyruvate Fermentation ◽  
Substrate Level ◽  
Fermentative Growth

ABSTRACT The amount of energy that can be conserved via halorespiration byDesulfitobacterium dehalogenans JW/IU-DC1 was determined by comparison of the growth yields of cells grown with 3-chloro-4-hydroxyphenyl acetate (Cl-OHPA) and different electron donors. Cultures that were grown with lactate, pyruvate, formate, or hydrogen as an electron donor and Cl-OHPA as an electron acceptor yielded 3.1, 6.6, 1.6, and 1.6 g (dry weight) per mol of reduction equivalents, respectively. Fermentative growth on pyruvate yielded 14 g (dry weight) per mol of pyruvate oxidized. Pyruvate was not fermented stoichiometrically to acetate and lactate, but an excess of acetate was produced. Experiments with 13C-labeled bicarbonate showed that during pyruvate fermentation, approximately 9% of the acetate was formed from the reduction of CO2. Comparison of the growth yields suggests that 1 mol of ATP is produced per mol of acetate produced by substrate-level phosphorylation and that there is no contribution of electron transport phosphorylation whenD. dehalogenans grows on lactate plus Cl-OHPA or pyruvate plus Cl-OHPA. Furthermore, the growth yields indicate that approximately 1/3 mol of ATP is conserved per mol of Cl-OHPA reduced in cultures grown in formate plus Cl-OHPA and hydrogen plus Cl-OHPA. Because neither formate nor hydrogen nor Cl-OHPA supports substrate-level phosphorylation, energy must be conserved through the establishment of a proton motive force. Pyruvate ferredoxin oxidoreductase, lactate dehydrogenase, formate dehydrogenase, and hydrogenase were localized by in vitro assays with membrane-impermeable electron acceptors and donors. The orientation of chlorophenol-reductive dehalogenase in the cytoplasmic membrane, however, could not be determined. A model is proposed, which may explain the topology analyses as well as the results obtained in the yield study.

Metabolism of lactate by mature boar spermatozoa

1997 ◽  
Vol 9 (2) ◽  
pp. 227 ◽  
Author(s):  
A. R. Jones
Keyword(s):  
Lactate Dehydrogenase ◽  
Nicotinamide Adenine Dinucleotide ◽  
Energy Charge ◽  
High Energy ◽  
The Other ◽  
Glycolytic Metabolism ◽  
Lactate Transport ◽  
Lactate Dehydrogenase Isozymes ◽  
Charge Potential ◽  
Boar Spermatozoa

Boar sperm oxidatively metabolized fructose, glucose, glycerol, glycerol 3-phosphate and lactate to CO2 but pyruvate produced only small amounts of CO2 and this was almost completely prevented when endogenous glycolytic metabolism was inhibited. Lactate was the preferred substrate over fructose, glycerol and glycerol 3-phosphate and when lactate was offered in the presence of pyruvate, lactate was preferentially oxidized to CO2. The rate of oxidation of fructose, glycerol and glycerol 3-phosphate was approximately halved in the presence of equi-molar concentrations of lactate and the metabolism of lactate was progressively decreased in the presence of increasing concentrations of mersalyl, an inhibitor of lactate transport. Sperm maintained a high energy charge potential when incubated with lactate as substrate in the presence or absence of bromopyruvate, an inhibitor of endogenous glycolytic metabolism. This evidence confirms that it is lactate, rather than pyruvate, that enters the mitochondria thereby constituting a lactate–pyruvate transport system in these cells for regenerating cytoplasmic nicotinamide adenine dinucleotide (NAD +). Electrophoretic examination of the lactate dehydrogenase isozymes from sperm and several other tissues of the boar showed that sperm contained almost entirely an isozyme which was not present in the other tissues.

Substrates for endogenous metabolism by mature boar spermatozoa

Reproduction ◽  
2000 ◽  
pp. 129-135 ◽  
Author(s):  
AR Jones ◽  
WA Bubb
Keyword(s):  
Energy Charge ◽  
High Energy ◽  
Glycolytic Pathway ◽  
Membrane Phospholipids ◽  
Atp Production ◽  
Metabolic Studies ◽  
Metabolic Substrates ◽  
Charge Potential ◽  
Endogenous Compounds ◽  
Boar Spermatozoa

Washed boar spermatozoa incubated in the absence of exogenous substrates maintained a high energy charge potential (ECP) for at least 10 h. Addition of bromopyruvate, an inhibitor of stage 2 of the glycolytic pathway, at any time during the incubation caused an immediate decrease in the ECP, indicating that the mobilization of endogenous compounds requires this section of the pathway for the production of lactate, the major mitochondrial substrate for ATP production. Some of the sources of the metabolic substrates have been identified, by NMR and metabolic studies, as di- or triglycerides, to produce glycerol, and membrane phospholipids for the production of glycerol 3-phosphate. Acetylcarnitine contributes acetyl groups early in the incubation; glycerylphosphorylcholine is degraded to glycerol 3-phosphate and choline after about 5 h, and acetate also accumulates after about 5 h. The presence of phosphorylcholine and phosphorylethanolamine later in the incubation indicates that phospholipids are also degraded to glycerol.

Inhibitory effects of bioaccessible anthocyanins and procyanidins from apple, red grape, cinnamon on α-amylase, α-glucosidase and lipase

2020 ◽  
pp. 1-9
Author(s):  
Pınar Ercan ◽  
Sedef Nehir El
Keyword(s):  
Inhibitory Activity ◽  
Digestive Enzymes ◽  
Positive Control ◽  
Anthocyanin Content ◽  
Inhibitory Effects ◽  
Total Anthocyanin ◽  
Total Anthocyanin Content ◽  
Before And After ◽  
Red Grape

Abstract. The goals of this study were to determine and evaluate the bioaccessibility of total anthocyanin and procyanidin in apple (Amasya, Malus communis), red grape (Papazkarası, Vitis vinifera) and cinnamon (Cassia, Cinnamomum) using an in vitro static digestion system based on human gastrointestinal physiologically relevant conditions. Also, in vitro inhibitory effects of these foods on lipid (lipase) and carbohydrate digestive enzymes (α-amylase and α-glucosidase) were performed with before and after digested samples using acarbose and methylumbelliferyl oleate (4MUO) as the positive control. While the highest total anthocyanin content was found in red grape (164 ± 2.51 mg/100 g), the highest procyanidin content was found in cinnamon (6432 ± 177.31 mg/100 g) (p < 0.05). The anthocyanin bioaccessibilities were found as 10.2 ± 1%, 8.23 ± 0.64%, and 8.73 ± 0.70% in apple, red grape, and cinnamon, respectively. The procyanidin bioaccessibilities of apple, red grape, and cinnamon were found as 17.57 ± 0.71%, 14.08 ± 0.74% and 18.75 ± 1.49%, respectively. The analyzed apple, red grape and cinnamon showed the inhibitory activity against α-glucosidase (IC50 544 ± 21.94, 445 ± 15.67, 1592 ± 17.58 μg/mL, respectively), α-amylase (IC50 38.4 ± 7.26, 56.1 ± 3.60, 3.54 ± 0.86 μg/mL, respectively), and lipase (IC50 52.7 ± 2.05, 581 ± 54.14, 49.6 ± 2.72 μg/mL), respectively. According to our results apple, red grape and cinnamon have potential to inhibit of lipase, α-amylase and α-glucosidase digestive enzymes.

In vitro α-amylase and α-glucosidase inhibitory activity of extracts and compounds from cultivated Artemisia dracunculus

Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
B Dursunoğlu ◽  
H Yuca ◽  
S Gözcü ◽  
H Özbek ◽  
Z Güvenalp ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
Artemisia Dracunculus

The Effects of Some Synthetic Compounds on In Vitro Fibrinolytic Activity Measured by Different Methods and the Relevance to Activity In Vivo

1972 ◽  
Vol 28 (03) ◽  
pp. 351-358
Author(s):  
A.J Baillie ◽  
A. K Sim
Keyword(s):  
Inhibitory Activity ◽  
Substrate Concentration ◽  
Fibrinolytic Activity ◽  
Synthetic Compounds ◽  
In Vitro Methods ◽  
Narrow Concentration Range

SummaryThe activity of several synthetic compounds, rated from good to poor (or inactive) fibrinolytic activators, has been assessed by two different commonly-used in vitro methods. Compounds shown to be active over a narrow concentration range in the hanging clot test were shown to be inhibitors of plasmin and trypsin in the casein-olytic test. The inhibitory activity of these compounds was shown to increase with increasing substrate concentration and apparent activity in the hanging clot test. Possible explanations and relevance of these observations are discussed.

Sign in / Sign up

Export Citation Format

Share Document