The Experts below are selected from a list of 2289 Experts worldwide ranked by ideXlab platform
T. B. Miller - One of the best experts on this subject based on the ideXlab platform.
-
Cellular mechanism of stimulation of renin secretion by the mercurial diuretic Mersalyl.
The Journal of pharmacology and experimental therapeutics, 1991Co-Authors: C S Park, P. S. Doh, C J Lee, D S Han, R. E. Carraway, T. B. MillerAbstract:The aim of the present study was to elucidate the cellular mechanism by which the mercurial diuretic Mersalyl stimulates renin secretion in rabbit renal cortical slices in vitro. The stimulatory effect of Mersalyl on renin secretion was rapid, reversible and concentration dependent. The stimulation was not dependent on the presence of ions such as Na+, Cl- and Ca++, and it was unaffected by inhibitors of Na+/K+/2Cl- cotransport, such as bumetanide and furosemide. However, the stimulation was blocked and reversed by thiols, such as L-cysteine and dithiothreitol. Furthermore, the maximal stimulatory effect of Mersalyl on renin secretion was not additive to that produced by the non-diuretic mercurial sulfhydryl reagent P-chloromercuriphenylsulfonate nor to that produced by the non-mercurial diuretic sulfhydryl reagent, ethacrynic acid. These results support the hypothesis that Mersalyl stimulates renin secretion by forming a reversible mercaptide bond with sulfhydryl groups, located perhaps on the plasma membrane of juxtaglomerular cells. These particular sulfhydryl groups appear to have no functional role in the diuretic action of Mersalyl.
Anibal E. Vercesi - One of the best experts on this subject based on the ideXlab platform.
-
Mitochondrial membrane protein thiol reactivity with N-ethylmaleimide or Mersalyl is modified by Ca2+: correlation with mitochondrial permeability transition
Biochimica et biophysica acta, 1997Co-Authors: Alicia J. Kowaltowski, Anibal E. Vercesi, Roger F. CastilhoAbstract:Abstract The content of mitochondrial membrane protein thiol groups accessible to react with the monofunctional thiol reagents Mersalyl or N-ethylmaleimide (NEM) was determined using Ellman's reagent. Deenergized mitochondria incubated in the presence of Ca2+ (0–500 μM) undergo a very significant decrease in the content of membrane protein thiols accessible to NEM, and an increase in the content of thiols accessible to Mersalyl. This process is time-dependent and inhibited by Mg2+, ruthenium red and ADP, but not by cyclosporin A. This suggests that Ca2+ binding to the inner mitochondrial membrane promotes extensive alterations in the conformation of membrane proteins that result in location changes of thiol groups. The relationship between these alterations and mitochondrial membrane permeability transition was studied through the effect of NEM and Mersalyl on mitochondrial swelling induced by Ca2+ plus t-butyl hydroperoxide (t-bOOH) or Ca2+ plus the thiol cross-linkers 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid (DIDS) or phenylarsine oxide (PhAsO). We observed that the hydrophobic thiol reagent NEM inhibits the effects of t-bOOH, DIDS and PhAsO, while the hydrophilic thiol reagent Mersalyl inhibits only the effect of DIDS. Permeability transition in all the situations studied is accompanied by a significant decrease in the total membrane protein thiol content. In addition, mitochondrial membrane permeabilization induced by PhAsO is inhibited by EGTA, but not by ruthenium red. This result suggests that PhAsO leads to permeability transition through a mechanism independent of intramitochondrial Ca2+-induced alterations of thiol group reactivity, but dependent on Ca2+ binding to an extramitochondrial site. This site is sensitive to extramitochondrial Ca2+ concentrations in range of 1–50 μM.
-
Calcium transport by corn mitochondria : evaluation of the role of phosphate.
Plant physiology, 1992Co-Authors: Marco Aurelio Pedron E Silva, Eva G. S. Carnieri, Anibal E. VercesiAbstract:Mitochondria from some plant tissues possess the ability to take up Ca(2+) by a phosphate-dependent mechanism associated with a decrease in membrane potential, H(+) extrusion, and increase in the rate of respiration (AE Vercesi, L Pereira da Silva, IS Martins, CF Bernardes, EGS Carnieri, MM Fagian [1989] In G Fiskum, ed, Cell Calcium Metabolism. Plenum Press, New York, pp 103-111). The present study reexamined the nature of the phosphate requirement in this process. The main observations are: (a) Respiration-coupled Ca(2+) uptake by isolated corn (Zea mays var Maya Normal) mitochondria or carbonyl cyanide p-trifluoromethoxyphenylhydrazone-induced efflux of the cation from such mitochondria are sensitive to Mersalyl and cannot be dissociated from the silmultaneous movement of phosphate in the same direction. (b) Ruthenium red-induced efflux is not affected by Mersalyl and can occur in the absence of phosphate movement. (c) In Ca(2+)-loaded corn mitochondria, Mersalyl causes net Ca(2+) release unrelated to a decrease in membrane potential, probably due to an inhibition of Ca(2+) cycling at the level of the influx pathway. It is concluded that corn mitochondria (and probably other plant mitochondria) do possess an electrophoretic influx pathway that appears to be a Mersalyl-sensitive Ca(2+)/inorganic phosphate-symporter and a phosphate-independent efflux pathway possibly similar to the Na(2+)-independent Ca(2+) efflux mechanism of vertebrate mitochondria, because it is not stimulated by Na(+).
C S Park - One of the best experts on this subject based on the ideXlab platform.
-
Cellular mechanism of stimulation of renin secretion by the mercurial diuretic Mersalyl.
The Journal of pharmacology and experimental therapeutics, 1991Co-Authors: C S Park, P. S. Doh, C J Lee, D S Han, R. E. Carraway, T. B. MillerAbstract:The aim of the present study was to elucidate the cellular mechanism by which the mercurial diuretic Mersalyl stimulates renin secretion in rabbit renal cortical slices in vitro. The stimulatory effect of Mersalyl on renin secretion was rapid, reversible and concentration dependent. The stimulation was not dependent on the presence of ions such as Na+, Cl- and Ca++, and it was unaffected by inhibitors of Na+/K+/2Cl- cotransport, such as bumetanide and furosemide. However, the stimulation was blocked and reversed by thiols, such as L-cysteine and dithiothreitol. Furthermore, the maximal stimulatory effect of Mersalyl on renin secretion was not additive to that produced by the non-diuretic mercurial sulfhydryl reagent P-chloromercuriphenylsulfonate nor to that produced by the non-mercurial diuretic sulfhydryl reagent, ethacrynic acid. These results support the hypothesis that Mersalyl stimulates renin secretion by forming a reversible mercaptide bond with sulfhydryl groups, located perhaps on the plasma membrane of juxtaglomerular cells. These particular sulfhydryl groups appear to have no functional role in the diuretic action of Mersalyl.
Martin Klingenberg - One of the best experts on this subject based on the ideXlab platform.
-
The reconstituted ADP/ATP carrier can mediate H+ transport by free fatty acids, which is further stimulated by Mersalyl
The Journal of biological chemistry, 1994Co-Authors: Nickolay Brustovetsky, Martin KlingenbergAbstract:In a reconstituted system, the participation of the ATP/ADP carrier (AAC) in the free fatty acid (FFA)-induced proton transport was demonstrated (i) by direct measuring of the proton transport through the membranes of AAC proteoliposomes and (ii) by monitoring of the transmembrane potential delta psi in AAC-cytochrome-c oxidase (COX)-coreconstituted proteoliposomes. FFA increased the initial rate of proton transport in AAC proteoliposomes and decreased delta psi in AAC-COX proteoliposomes. Inhibitors of AAC suppressed the effects of FFA. Without AAC or with inactive AAC, FFA cannot maintain proton leakage through the membrane. In these cases, even a small increase of delta psi was induced by FFA. These results demonstrate for the first time with purified components a participation of AAC in FFA-induced proton transport supporting an earlier suggestion (Skulachev, V.P. (1991) FEBS Lett. 294, 158-162). Mersalyl treatment of the AAC-COX proteoliposomes resulted in an increase of the AAC-mediated protonophoric action of FFA. Mersalyl also sensitized the protonophoric action of the FFA against nucleotides so that even guanine nucleotides, which are inactive in transport, become inhibitory. The effect of Mersalyl is rationalized in terms of a specific interaction with cysteine 159 being attracted as anion by surrounding positive charges. This might open a gate similarly as suggested for eosin 5-maleimide interaction (Majima, E., Koike, H., Hong, Y.-M., Shinohara, Y., and Terada, H. (1993) J. Biol. Chem. 268, 22181-22187) and, thus, transform the AAC into undirectional transport mode.
-
the reconstituted adp atp carrier can mediate h transport by free fatty acids which is further stimulated by Mersalyl
Journal of Biological Chemistry, 1994Co-Authors: Nickolay Brustovetsky, Martin KlingenbergAbstract:In a reconstituted system, the participation of the ATP/ADP carrier (AAC) in the free fatty acid (FFA)-induced proton transport was demonstrated (i) by direct measuring of the proton transport through the membranes of AAC proteoliposomes and (ii) by monitoring of the transmembrane potential delta psi in AAC-cytochrome-c oxidase (COX)-coreconstituted proteoliposomes. FFA increased the initial rate of proton transport in AAC proteoliposomes and decreased delta psi in AAC-COX proteoliposomes. Inhibitors of AAC suppressed the effects of FFA. Without AAC or with inactive AAC, FFA cannot maintain proton leakage through the membrane. In these cases, even a small increase of delta psi was induced by FFA. These results demonstrate for the first time with purified components a participation of AAC in FFA-induced proton transport supporting an earlier suggestion (Skulachev, V.P. (1991) FEBS Lett. 294, 158-162). Mersalyl treatment of the AAC-COX proteoliposomes resulted in an increase of the AAC-mediated protonophoric action of FFA. Mersalyl also sensitized the protonophoric action of the FFA against nucleotides so that even guanine nucleotides, which are inactive in transport, become inhibitory. The effect of Mersalyl is rationalized in terms of a specific interaction with cysteine 159 being attracted as anion by surrounding positive charges. This might open a gate similarly as suggested for eosin 5-maleimide interaction (Majima, E., Koike, H., Hong, Y.-M., Shinohara, Y., and Terada, H. (1993) J. Biol. Chem. 268, 22181-22187) and, thus, transform the AAC into undirectional transport mode.
R. E. Carraway - One of the best experts on this subject based on the ideXlab platform.
-
Cellular mechanism of stimulation of renin secretion by the mercurial diuretic Mersalyl.
The Journal of pharmacology and experimental therapeutics, 1991Co-Authors: C S Park, P. S. Doh, C J Lee, D S Han, R. E. Carraway, T. B. MillerAbstract:The aim of the present study was to elucidate the cellular mechanism by which the mercurial diuretic Mersalyl stimulates renin secretion in rabbit renal cortical slices in vitro. The stimulatory effect of Mersalyl on renin secretion was rapid, reversible and concentration dependent. The stimulation was not dependent on the presence of ions such as Na+, Cl- and Ca++, and it was unaffected by inhibitors of Na+/K+/2Cl- cotransport, such as bumetanide and furosemide. However, the stimulation was blocked and reversed by thiols, such as L-cysteine and dithiothreitol. Furthermore, the maximal stimulatory effect of Mersalyl on renin secretion was not additive to that produced by the non-diuretic mercurial sulfhydryl reagent P-chloromercuriphenylsulfonate nor to that produced by the non-mercurial diuretic sulfhydryl reagent, ethacrynic acid. These results support the hypothesis that Mersalyl stimulates renin secretion by forming a reversible mercaptide bond with sulfhydryl groups, located perhaps on the plasma membrane of juxtaglomerular cells. These particular sulfhydryl groups appear to have no functional role in the diuretic action of Mersalyl.