Biomedical subjects

Branka Zivanović

Publications and source records attributed to Branka Zivanović.

3 recordsLinked to original sources

PubMed2005

Ca2+ and H+ ion fluxes near the surface of gravitropically stimulated Phycomyces sporangiophore.

The single-celled fungus Phycomyces blakesleeanus forms vertically oriented sporangiophores from hyphae, which display a negative gravitropic response. Longitudinal growth and gravitropic bending of these sporangiophores were measured with noninvasive H(+) and Ca(2+) ion-selective microelectrode measurements. The directions of H(+) and Ca(2+) fluxes, recorded at different locations of sporangiophores, were opposite when the sporangiophores were kept in vertical position. Ca(2+) fluxes were in most experiments positive (efflux), while H(+) fluxes were negative (influx). The direction of ion fluxes depended on developmental stage of sporangiophores and changed with gravistimulation.

Calcium↗

PubMed2005

A new model system for investigation of ionic channels in filamentous fungi: evidence for existence of two K+-permeable ionic channels in Phycomyces blakesleeanus.

A technique was developed to obtain viable cytoplasmic droplets, enabling the formation of a gigaohm seal. Such cytoplasmic droplets can be used for characterization of plasma membrane ion channels from filamentous fungi by patch-clamp technique. Two K(+) ionic channels are characterized with a conductance of 43 pS and 74 pS.

Cell Membrane Permeability↗

PubMed2005

Changes in Chenopodium rubrum seeds with aging.

We studied antioxidative system, germination, growth, and flowering in vitro in Chenopodium rubrum seeds of different ages. Peroxidase, superoxide dismutase, and catalase activity, as well as glutathione status, were determined in 2.5-h imbibed seeds. Germination was tested under controlled conditions. Growth and flowering of plants were tested in vitro. The enzyme activities and glutathione content were higher in younger seeds. Germination declines with seed age. Plants derived from older seeds were smaller, and flowering percentage was lower compared to plants derived from younger seeds. Gibberellic acid reduced the difference in growth and flowering between plants derived from seeds different in age.

Aging↗