oxonol-v and 2-aminoisobutyric-acid

Accumulation of 2-aminoisobutyrate by mouse ascites tumour cells was studied in circumstances where nigericin reversed the normal direction of the Na+ concentration gradient. The membrane potential (delta psi) was assayed using oxonol V as a voltage-sensitive probe. The amino acid gradient (delta mu A) that formed did not significantly exceed the likely magnitude of the Na+ electrochemical gradient when this was in the range 2-6 kJ mol-1. When delta-Na mu increased up to 11 kJ mol-1, delta mu A was almost constant at 7-8 kJ mol-1. The observations indicate that when delta psi is large changes in cellular [Na+] in the range 16-80 mM scarcely affect delta mu A.

Topics: Algorithms; Amino Acids; Aminoisobutyric Acids; Animals; Ascites; Biological Transport, Active; Electrochemistry; Isoxazoles; Mice; Neoplasms, Experimental; Nigericin; Sodium; Tumor Cells, Cultured