Compartmental responses to acute osmotic stress in Leishmania major result in rapid loss of Na+ and Cl-.
Journal Article
The elemental composition of the cytoplasm, electron dense vacuoles, and heterochromatin and euchromatin regions of the nucleus of Leishmania major promastigotes was measured by electron probe X-ray microanalysis under iso-osmotic conditions (305 mOsM) and shortly after a sudden increase (to 615 mOsM) or decrease (to 153 mOsM) in the osmolality of the buffer in which they were suspended. In response to acute hypotonicity a complete loss of Na from the electron dense vacuoles and an approximately threefold decrease in the Na concentrations in the cytoplasm and the nuclear regions occurred, together with an approximately threefold decrease in Cl content in each compartment and a smaller (approx. 1.2-fold) decrease in K content. Thus, in addition to the rapid change in shape and release of amino acids known to occur in response to acute hypo-osmotic stress, a major efflux of Na and Cl, and, to a lesser extent, of K, also occurs. In response to acute hypertonicity Na in the acidocalcisomes did not change but Na content of the cytoplasm decreased by 33%. A small increase in the S content of the cytoplasm and the electron dense vacuolar compartments occurred. No changes were detectable in Ca or Zn content in any of the compartments examined in response to hypotonicity or hypertonicity.
Full Text
Duke Authors
Cited Authors
- LeFurgey, A; Ingram, P; Blum, JJ
Published Date
- February 2001
Published In
Volume / Issue
- 128 / 2
Start / End Page
- 385 - 394
PubMed ID
- 11223400
Pubmed Central ID
- 11223400
International Standard Serial Number (ISSN)
- 1095-6433
Digital Object Identifier (DOI)
- 10.1016/s1095-6433(00)00319-6
Language
- eng
Conference Location
- United States