RE: Physical properties of isotopes? -- H-2 question

["Bradshaw, Keith" <Keith.Bradshaw@NNC.CO.UK>]

Jaro



Yes, someone has tried to raise mice on heavy water.  I've forgotten the

details, but I don't think the mice did too well.  The difference in

reaction rates between protium and deuterium isn't slight, it's

several-fold, and can't support the metabolic rate of higher animals.



The "kinetic isotope effect" has been used to study reaction mechanisms in

organic chemistry.  It's quite possible to observe different reaction rates

for different isotopes of hydrogen and carbon, although with the latter, the

difference is only a few percent.  I've got some notes on this somewhere (at

home, not here).



Personal views only



keith.bradshaw@nnc.co.uk







Keith Bradshaw

keith.bradshaw@nnc.co.uk

New NNC web site: http://www.nnc.co.uk



> -----Original Message-----

> From:	Franta, Jaroslav [SMTP:frantaj@AECL.CA]

> Sent:	Monday, September 24, 2001 1:29 PM

> To:	radsafe@list.vanderbilt.edu

> Subject:	RE: Physical properties of isotopes? -- H-2 question

> 

>  Ruth, you wrote :

>  

> The only exception to this that I know of is the the differing atomic

> weights of the isotopes of hydrogen (H-1, H-2, H-3) can result in slightly

> different reaction rates. 

>  

> Would you please, if you can, tell us whether the above fact has any

> bearing on the toxicity - if any - of heavy water ?

> The reason I'm asking is that recently I was told that drinking a glass or

> two of high-concentration or pure D2O would kill you, due to the toxicity.

> 

> I'm very dubious about this, but haven't seen anything that solidly

> refutes this notion either (I thought that there wouldn't be any

> difference, even if every hydrogen atom in our bodies were replaced by a

> deuteron.... am I mistaken ?  .....maybe somebody, somewhere, has tried

> raising mice on a heavy-hydrogen diet ??).

>  

> Thanks

>  

> Jaro





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