Na+-dependent, alpha-adrenergic mobilization of intracellular (mitochondrial) Ca2+ in brown adipocytes.
1984 (English)In: European Journal of Biochemistry, ISSN 0014-2956, E-ISSN 1432-1033, Vol. 141, no 1, 187-193 p.Article in journal (Refereed) Published
The existence and significance of a hormone-sensitive, rapidly mobilizable intracellular pool of Ca2+ in hamster brown-fat cells was investigated with 45Ca2+-labelling techniques. It was shown that such a pool existed and was probably located within the abundant mitochondria. It was rapidly mobilized by norepinephrine (median effective concentration 50 nM) through alpha-adrenergic mechanisms. The mobilization of Ca2+ from the intracellular stores (mitochondria) required the presence of extracellular Na+, but not of Ca2+, K+ or Mg2+. It is concluded that the experiments are in agreement with a hypothesis linking the mobilization of intracellular Ca2+ pools with an alpha-adrenergically-induced increase in plasma membrane Na+ permeability (observed as a membrane depolarization), and a subsequent activation of the mitochondrial Na+/Ca2+ exchange, leading to mobilization of mitochondrial Ca2+ and the mediation of alpha-adrenergic effects as a result of an elevated cytosolic Ca2+ level.
Place, publisher, year, edition, pages
1984. Vol. 141, no 1, 187-193 p.
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:kau:diva-29828PubMedID: 6327307OAI: oai:DiVA.org:kau-29828DiVA: diva2:657586