Ca2+Uptake Solution for Assaying Ca2+Transport in Mitochondria:

2014 ◽  
Vol 2014 (2) ◽  
pp. pdb.rec076208
Keyword(s):  
Transport In Mitochondria

Substrate anion transport in mitochondria

Biochimie ◽  
1973 ◽  
Vol 55 (6-7) ◽  
pp. 717-725 ◽  
Author(s):  
A. Brouwer ◽  
G.G. Smits ◽  
J. Tas ◽  
A.J. Meijer ◽  
J.M. Tager
Keyword(s):  
Anion Transport ◽  
Transport In Mitochondria

scholarly journals Lactic acid secretion by human neutrophils. Evidence for an H+ + lactate- cotransport system.

1992 ◽  
Vol 100 (2) ◽  
pp. 341-367 ◽  
Author(s):  
L Simchowitz ◽  
J A Textor
Keyword(s):  
Lactic Acid ◽  
Steady State ◽  
Ph Dependence ◽  
Transport Systems ◽  
Human Neutrophils ◽  
Bathing Medium ◽  
Monocarboxylate Transport ◽  
Cotransport System ◽  
Ph Stat ◽  
Transport In Mitochondria

The pathway by which L-lactate (Lac) crosses the plasma membrane of isolated human neutrophils was investigated. The influx of [14C]Lac from a 2 mM Lac, 145 mM Cl-, 5.6 mM glucose medium was approximately 1.5 meq/liter of cell water.min and was sensitive to the organomercurial agent mersalyl (apparent Ki approximately 20 microM), to alpha-cyano-4-hydroxycinnamate (CHC), the classical inhibitor of monocarboxylate transport in mitochondria, and to UK-5099 (apparent Ki approximately 40 microM), a more potent analogue of CHC. Transport was also strongly blocked (greater than 80%) by 1 mM of either 3,5-diiodosalicylic acid, MK-473 (an indanyloxyacetate derivative), or diphenyl-amine-2-carboxylate, and by 0.4 mM pentachlorophenol, but not by 1 mM ethacrynic acid, furosemide, or the disulfonic stilbenes SITS or H2DIDS. One-way [14C]Lac efflux from steady-state cells amounted to approximately 6 meq/liter.min and was likewise affected by the agents listed above. Influx, which was membrane potential insensitive and Na+ independent, displayed a strong pH dependence: extracellular acidification enhanced uptake while alkalinization inhibited the process (pK' approximately 5.7 at 2 mM external Lac). The rate of [14C]Lac influx was a saturable function of external Lac, the Km being approximately 7 mM. Steady-state cells exhibited an intracellular Lac content of approximately 5 mM and secreted lactic acid into the bathing medium a a rate of approximately 4 meq/liter.min. Secretion was completely suppressed by 1 mM mersalyl which inactivates the carrier, leading to an internal accumulation of Lac. That the Lac carrier truly mediates an H+ + Lac- cotransport (or formally equivalent Lac-/OH- exchange) was documented by pH-stat techniques wherein an alkalinization of poorly buffered medium could be detected upon the addition of Lac; these pH changes were sensitive to mersalyl. Thus, the Lac carrier of neutrophils possesses several features in common with other monocarboxylate transport systems in erythrocytes and epithelia.

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