Page 15 - Chow LIfe - Fall 2021.pdf
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implicated in slower drug processing in Greyhounds. Thanks to the collaborative efforts of the Chow Chow
Club, Inc. and CHF, researchers are now studying
A different enzyme that supports cytochrome P450 this unique Chow Chow mutation. They will examine
enzyme function, known as cytochrome P450 how this mutation affects cytochrome P450 enzyme
oxidoreductase or POR, was also found in varied function in Chows. They will also determine how
quantities in different dog breeds. In vitro testing prevalent the mutation is within the Chow Chow
(performed in a test tube or outside of a living breed and if it is present in other dog breeds.
being) confirmed that two variations in the POR-
coding gene found most commonly in Greyhounds These important studies may ultimately lead to
significantly reduced the efficiency of CYP2B11 genetic tests that veterinarians can use in the clinic
enzyme function. Evidence now showed that altered to choose the safest and most effective drugs for each
function in the CYP2B11 enzyme and one of its individual patient. Visit akcchf.org to learn how you
supporting enzymes could be responsible for adverse and your dog can participate in this study or provide
drug reactions in some dog breeds. a donation to help support research. Together, we will
ensure a healthier, happier future for all dogs.
The breakthrough came when investigators recently
identified a variation in the CYP2B11 gene in
Greyhounds that is responsible for its decreased
function in this breed and several other breeds. The
mutation causes abnormal mRNA molecules and
therefore decreased enzyme levels and slower drug
metabolism. Results, published in Scientific Reports,
reported that this mutation was also found in other
breeds including the Labrador Retriever and Golden
Retriever.
A unique Chow Chow mutation –
During these studies, the research team found a
different genetic mutation affecting the CYP2B11
enzyme in Chow Chows. The genetic variant also
appears to result in slower drug metabolism but
is not the exact same DNA sequence found in
Sighthounds and other breeds as described above.
Health Committee Report: Lew Klein
The CCCI funded AKC CHF grant at Dr. Court’s to study drugs dexmedetomidine, buprenorphine and
Lab in Washington State University (WSU) is hydromorphone. A CCCI member/breeder reported
studying what causes potentially lethal reactions from to WSU that according to her personal experience,
anesthetic and sedative drugs in some Chows and is her lines have a “problem” with the drugs midazolam,
making additional progress. A special thanks goes acepromazine, butorphanol and trazodone but
out to Amy (Young) Frick, who not only volunteered buprenorphine, tramadol, hydromorphone are
her dogs for DNA sampling but is also taking DNA “safe”. WSC will be researching this to see if there are
kits to the Atlanta Specialty to ask for donors, as additional enzymes or gene mutations in addition to
well over social media. If other ChowLife readers CYP2B11.
would also like to participate via mail, Dr Court or
I would be glad to mail you a DNA collection kit/ Dr Court is attending the CCCI 2021 National
instructions because we still need more Chows to Specialty in Niagara Falls, New York to answer any
fulfill the minimum required statistical sample of 300. questions about the study at the Health Committee
The participation criterion is “any” AKC registered table on October 6th and 7th and will be giving a
Chows, whether they have a history of being sedated/ one hour seminar about the study on October 6th.
anesthetized or not but only one sibling from the Hope to see you at the CCCI 2021 National Specialty
same Sire/Dam pair. in New York and the 2022 Specialty in Pennsylvania,
where DNA collection kits will be distributed and/or
As mentioned in the last Chow Life issue, WSU collected.
discovered a CYP2B11 gene mutation that causes Lew Klein, CCCI Health Committee
a marked reduction in the functioning of the main lewis.Klein555@gmail.com
liver enzyme that metabolizes drugs. WSU assays also
discovered that the drugs “ketamine and tramadol Dr. Court, WSU Pharmacogenomics Laboratory
are likely to be problematic”, while “trazodone, michael.court@wsu.edu
butorphanol and midazolam are safe”. They also plan (Note: A copy of the Consent & Anesthia
History Form can be found on pages 75-77)
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