influence of ethanol

Stephen R. Lasky Stephen_Lasky at brown.edu
Mon Feb 19 09:03:06 EST 1996


In article <Dn0y4n.4zz at uia.ua.ac.be>, verlooy at uia.ua.ac.be wrote:

Joris:  This is a common problem encountered when working with lipophilic
drugs (steroid hormones, etc) and is the reason that most people run
ethanol controls.  If you are getting an ethanol effect there may be a
couple of ways around it.  First, and easiest, is to make your stock
solution more concentrated.  We generally make our VD3 working stock
solutions at 2 e-4 M, but this comes from a stock solution of 2 to 5
e-3M.  If we were to need concentrations of the hormone that required 0.1%
ethanol using the working stock solution, we could use the more
concentrated stock solution.  Another possiblity is to dissolve the
steroid in some other solvent such as DMSO or isopropanol.  But then you
have to determine whether those vehicles cause any effects at the highest
concentrations you will need to use them at.  

Those are the first things that I would try.  

SRLasky

> Hi,
> 
> 
> Can someone help me with this problem?
> 
> I do some research on the influence of steroids on chondrocytes in vitro.
> I incubate the cells with stimulationmedium (= DMEM with one of the 
> steroids)and measure then some cell-growth-parameters. 
> Some of the steroids I use, I can only dissolve in ethanol. The highest 
> concentration of ethanol is 0.1% (because theconcentration of the
steroid has to 
> be that high). 
> The problem now is that 0.1% ethanol has an effect on the measured
parameters in 
> comparison with the blanco medium. This makes it very difficult to
differentiate 
>  between the effect of the steroid and the effect of ethanol.
> 
> Has someone experienced these problems.
> 
> (It is very difficult to lower the concentration of ethanol without
lowering the 
> concentration of steroid.)
> 
> 
> Joris VERLOOY
> Dept. Pediatrics (T4)
> University of Antwerp (U.I.A.)
> Belgium
> verlooy at uia.ua.ac.be

-- 
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Stephen R. Lasky Ph.D.   Brown U/Roger Williams Medical Center,  Providence, RI.   
Phone: 401-456-5672     Fax: 401-456-6569     e:mail: Stephen_Lasky at brown.edu
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America may be unique in being a country which has leapt from barbarism to decadence without touching civilization.  John O'Hara.
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