Search results for "INTRACELLULAR PH"
showing 7 items of 37 documents
Locust flight metabolism studied in vivo by 31P NMR spectroscopy
1991
Flight metabolism of locusts has been extensively studied, but biochemical and physiological methods have led to conflicting results. For this reason the non-invasive and non-destructive method of 31P NMR spectroscopy was used to study migratory locusts, Locusta migratoria, at rest and during flight. 1. In the flight muscle of resting locusts the ratio of phosphoarginine to ATP was the same whether determined by NMR (1.76) or biochemically, but the NMR-visible content of inorganic phosphate (Pi) was only 40% of ATP, i.e., much lower than total Pi as determined biochemically. This suggests that most of the Pi in flight muscle is not free, and hence not available as substrate or effector for …
THE FINE STRUCTURE OF O2 Hb BINDING IN ANIMALS: SALMO IRIDEUS
1980
Publisher Summary This chapter discusses the experimental results on study of the fine structure of O 2 Hb binding in animals. It is evident that the n ( S ) function represents a new tool to look at homotropic interactions, both qualitatively and quantitatively. At the moment, there are four applications: (1) study of molecular mechanism; (2) study of effectors, also pharmacological; (3) improved characterization of O 2 Hb binding, also in pathological cases; and (4) comparative studies in animals. Whole blood of fish is also investigated because usually there are found several hemoglobins. During registration of the O 2 binding curve, pH is not kept constant. Assuming that the Donnan fact…
A minireview on NHE1 inhibitors. A rediscovered hope in oncohematology.
2015
Background: Na+/H+ exchanger-1 (NHE-1) is involved in pH regulation and is up-regulated in different malignancies. Activation of NHE-1 is one way for allowing cells to avoid intracellular acidification and protect them against apoptosis. Inhibitors of NHE-1 are able to decrease intracellular pH and induce apoptosis. Some statins can also act by partial inhibition of NHE-1. This review presents progress in understanding the mechanisms of action of these inhibitors, connections with certain genetic mutations and acquired treatment resistance, as well as new patents on them. Methods: A MEDLINE search for original and review articles using key terms, Na+/H+ exchanger, leukemia, cariporide, and …
Effects of Extracellular Acidosis on Glial Cell Intracellular pH: Evidence for a Glial Spatial H+-Buffering Mechanism?
1994
Acidosis and in particular lactacidosis from anaerobic metabolism are considered of primary significance among the consequences of cerebral ischemia, seizures,, and head injury (Siesjo 1981). A marked decrease in brain tissue pH has been demonstrated in cerebral ischemia - even more so in hyperglycemic subjects - where lactic acid may accumulate to 20–30 mM and higher concentrations (Rehncrona et al. 1980; Katsura et al. 1991). Tissue pH may drop to pH 5.5 (Chopp et al. 1988). In consequence, acidosis has since long been suspected as a mediator of brain damage (Siesjo 1981).
MUSCLE BIOENERGETICS IN OBESE ZUCKER RATS
1994
International audience; Abstract: The purpose of this study was to investigate the energetic metabolism in obese Zucker rats, using phosphorus nuclear magnetic resonance spectroscopy at rest and during a 2-Hz muscle stimulation and subsequent recovery. Animals were anesthetized with ketamine (150 mg/kg ip). Fed obese rats and 2-day-fasted obese rats were compared with their normally fed and 2-day-fasted lean litter mates. No differences were found between the two groups for ATP, total creatine, phosphocreatine (PCr), and intracellular pH. Starvation in lean rats resulted in a significant fall in inorganic phosphate (Pi), increased resting ADP level, and decreased PCr and ADP recovery after …
Swelling, Intracellular Acidosis, and Damage of Glial Cells
1996
Cerebral ischemia and severe head injury among others are associated with a limited availability of oxygen, leading to cell catabolism as well as anaerobic glycolysis. Resulting metabolites, such as arachidonic- and lactic acid, can be expected to leak into perifocal brain areas, contributing there to cytotoxic swelling and damage of neurons and glia. Since elucidation of mechanisms underlying cell swelling and damage in the brain is difficult in vivo, respective investigations were carried out in vitro using suspended glial cells. Thereby, effects of arachidonic acid (AA) and of lactacidosis on glial cell volume, intracellular pH (pHi), and cell damage were analyzed utilizing flow cytometr…
Flow cytometric analysis of chronic and acute toxicity of copper(II) on the marine dinoflagellateAmphidinium carterae
2001
Background Copper(II) is a heavy metal whose levels have increased in some marine ecosystems to polluting levels. Dinoflagellates, an important phytoplankton group, are at the base of aquatic food chains and bioaccumulation of copper by these microorganisms can result in complex ecosystem alterations, so we investigated how copper disturbs those cells. Methods Cytotoxic effects of sublethal and lethal copper concentrations ranging from 4.2 nM (control condition) to 3.13 μM estimated labile copper were studied in batch cultures of Amphidinium carterae. Cell morphology, motility, autofluorescence, and fluorescein diacetate (FDA)–dependent fluorescence generation were evaluated by flow cytomet…