Electrochemical studies of zinc in zinc-insulin solution.
The electrochemical determination of zinc arising from zinc-insulin complexes was investigated and it was demonstrated that zinc in zinc-insulin solution can be measured in the presence of dissolved oxygen by square-wave anodic stripping voltammetry (SWASV) at mercury thin-film electrodes on glassy carbon disc minielectrode and cylindrical carbon fibre microelectrode substrates. Reoxidation signals arise from complexed zinc at low insulin concentrations (< 100 nmol l-1) and from labile zinc at higher concentrations; the latter can be quantified through linear calibration curves. Batch injection analysis with SWASV was successfully tested for the determination of zinc in zinc-insulin solutions in small sample volumes. Since intracellularly stored insulin exists in the form of a zinc-insulin complex, these techniques are very promising for the indirect study of insulin release from pancreatic beta-cells.
Barbosa
R M
RM
Centro de Neurociências de Coimbra, Universidade de Coimbra, Portugal.
Rosário
L M
LM
Brett
C M
CM
Brett
A M
AM
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D004563:Electrochemistry; D007328:Insulin / Q000737:chemistry*; D008969:Molecular Sequence Data; D012996:Solutions; D015032:Zinc / Q000737:chemistry*
D007328:Insulin; D012996:Solutions; D015032:Zinc