Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/64791
Type: Artigo de periódico
Title: ENERGIZATION-DEPENDENT CA-2+ ACCUMULATION IN TRYPANOSOMA-BRUCEI BLOOD-STREAM AND PROCYCLIC TRYPOMASTIGOTES MITOCHONDRIA
Author: VERCESI, AE
DOCAMPO, R
MORENO, SNJ
Abstract: The permeabilization of Trypanosoma brucei procyclic and bloodstream trypomastigotes with digitonin permitted the quantitative estimation of a mitochondrial membrane potential of the order of 130-140 mV, in both forms, using safranine O. Dependence on substrate oxidation and response of the procyclic mitochondrial membrane potential to phosphate, FCCP, valinomycin, and Ca2+ indicate that these mitochondria behave similarly to vertebrate mitochondria regarding the properties of their electrochemical proton gradient. In contrast, in bloodstream mitochondria, development of a membrane potential was independent of substrate oxidation and dependent on hydrolysis of ATP by the mitochondrial oligomycin-sensitive ATPase, as demonstrated by collapse of the membrane potential by oligomycin and its insensitivity to the respiratory chain-inhibitor antimycin A. Mitochondria of T. brucei bloodstream forms were also able to take up Ca2+ by an electrophoretic mechanism. This is the first report of the presence of a Ca2+ transport mechanism in an eukaryotic cell devoid of complete tricarboxylic acid cycle and respiratory chain, the activities of which are known to be regulated by changes in intramitochondrial calcium concentration in other cells.
Subject: TRYPOMASTIGOTES
CALCIUM
MITOCHONDRIA
TRYPANOSOMA-BRUCEI
Country: Holanda
Editor: Elsevier Science Bv
Rights: fechado
Identifier DOI: 10.1016/0166-6851(92)90174-I
Date Issue: 1992
Appears in Collections:Unicamp - Artigos e Outros Documentos

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