>He's had corrective surgery and our vet managed to stop his resultant
>hydronephrosis and his kidney numbers are good.  We know that with
>cystine stones there sometimes can be a kidney variant where cystine
>is not processed properly, but we do not at this point suspect that.
 
Hi Sukie ~
 
Here's what I know about Cystine.  *Two amino acids cysteine and cystine
are closely related.  Each molecule of cystine consist of two molecules
of cysteine joined together.
 
Cysteine is very unstable and is easily converted to L-cystine, but each
form is also capable of converting to the other as needed.  Both are
sulfur-containing amino acids that aid in the formation of skin and are
important in detoxification.  ** A sulfur containing amino-acid allows
cysteine to bond in a special way and maintain the structure of proteins
in the body.  Cysteine is a component of glutathione.  However this is
rarely used as a dietary supplement.  A more common amino acid used in
supplementation is called NAC or N-Acetyl-Cysteine.  You should check to
see which is included in the food, as NAC is the more commonly favored
for most high-protein foods.
 
**Here are the results of trials with NAC:
 
One study found that daily amounts of 1.2 grams or more could lead to
oxidative damage.  Extremely large amounts of cysteine, the amino acid
from which NAC is derived may be toxic to nerve cells in rats.  NAC may
increase urinary zinc excretion.  Therefore supplemental zinc and copper
should be added when supplementing with NAC for extended periods.
 
No reference to stones in this text either.
 
*We know that Cysteine works best in the presence of selenium and
vitamin E as it helps to detoxify harmful toxins and protects the body
from radiation damage.  However vitamin B-6 is absolutely necessary
for cysteine synthesis, which may not take place as it should in the
presence of chronic disease.
 
*The bigger caution is that it inactivates insulin.  So if there is any
diabetes this supplement should not be taken.  There is a rare genetic
disorder called cystinuria which leads to the formation of cystine kidney
stones.  Otherwise I can find no other referencde to kidney stone
formation from supplementing with this amino acid, provided all of the
complimentary criteria are met.
 
My thoughts go along these lines.  When using a more obscure amino acid,
or one in which deficiencies have not yet been defined, you get into the
dilemma of which other supplements to use to balance the whole thing out.
If you don't maintain that delicate balance of vitamins, minerals, and
supplements you can get into trouble.  Now these findings are for humans,
so it's important to know why the makers of these ferret foods put
certain ingredients in there in the first place.
 
Ref: (*) "Prescription  for Nutritional Healing," by Phyllis Balach, 1997.
         (There are later editions in bookstores)  ISBN# 0-89529-727-2
 
   (**)  "The Natural Pharmacy."  Lininger, Schuyler,DC (Ed.) 1999 by
          Healthnotes, Inc., ISBN# 0-7615-1967-X.
 
I hope this gives you a bit of information and can help.
 
Warmly ~
 
Mary L. Conley, ND, Herbalist
Conley Farm Organic Herbs
Online Classes
www.Herbgrow30.com
 
****************************************
From time immemorial it has been known that Providential Means have
placed in nature the prevention and cure of disease, by means of divinely
enriched herbs, plants, and trees.
 
          ~ Dr. Edward Bach
[Posted in FML issue 4569]