According to the company, the H0606.S9(AX) Pooled Human Liver S9 and H0606.C(AX) Pooled Human Liver Cytosol test systems have been prepared from tissue treated to preserve high AO (aldehyde oxidase) and XO (xanthine oxidase) activity.
Stephanie Helmstetter, senior manager of production and quality control at Sekisui XenoTech, explained in the press release: “Aldehyde oxidase activity, as measured by the oxidation of zaleplon to 5-oxo-zaleplon, phthalazine to 1-phthalazinone, and p-vanillin to vanillic acid, was on average 2- to 3-fold higher in human liver S9 prepared from HTK-preserved livers than UW-preserved livers.”
“Xanthine oxidase activity, as measured by the oxidation of 6-nitroquinazolinone to 6-nitroquinazolinedione, was on average over 5-fold higher in human liver S9 prepared from HTK-preserved livers than UW-preserved livers. Furthermore, preservation of livers in HTK or UW cold storage solutions did not lead to a significant difference in CYP activity,” she added.
The CRO added new dermal subcellular fraction test systems in February of this year as well, at which time the company told us the biggest demand had been coming from European countries where animal use in research is "highly restricted."