Try searching www.google.com for "calcium chelator calculator".
For example:
http://www.probes.com/lit/bioprobes34/section7.html
There are, of course, commercial programs that do this.
"Tobias Rose" <TRose at t-online.de> wrote in message
news:96ou23$1ft$01$1 at news.t-online.com...
> Hi!
>> I'm trying to isolate my leech neurons (Retzius) from synaptic input by
> using High Mg2+ (20mM) Ringer fluid.
> My question: What is the exact explanation for the achieved PSP
depression?
> Is it just a competitive effect of Mg2+ instead of Ca2+ running through
the
> presynaptic Ca2+ channels and thus preventing the intracellular vesicle
> exocytosis because of the absence of appropriate binding sites? Or am I
> missing something?
>> Addtitional: To achieve te same (and some other) effects I'm using
> lowCa2+/EGTA Ringer. Does anyone know a URL where I can find a table of
> binding rates, affinity constants etc. for EGTA/Ca2+ to calculate the
exact
> concentration of remaining free Ca2+?
>> And last: Is there anyone out there experienced in pharmacological effects
> on leech neurons? I'm looking for some methodical knowledge exchange...
>> best regards,
> Tobias
>