2024-03-29T11:25:36Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/826692022-11-17T02:08:08Zhdl_2115_20048hdl_2115_140Urinary free metanephrines measurement in dogs with adrenal gland diseases using a new simple liquid chromatography tandem mass spectrometry methodSasaki, NoboruIkenaka, YoshinoriInoue, YumikoIchise, TakahiroNagata, NoriyukiIshizuka, MayumiNakayama, Syouta MmNakamura, KensukeTakiguchi, Mitsuyoshicanineliquid chromatography tandem mass spectrometrynormetanephrinepheochromocytomaurinary metanephrines649Measurement of urinary metanephrines in spot samples is used for the diagnosis of canine pheochromocytoma (PC). We describe a simple analytical method based on liquid chromatography tandem mass spectrometry ( LC- MS/MS) for measuring free metanephrine (MN) and normetanephrine (NMN) in spot urine samples. Using the developed method, we evaluated the stability of urinary free-MN and free-NMN at various storing conditions. In addition, we assessed the feasibility of urinary free-MN and -NMN measurement for diagnosing PC. Urine samples were mixed with stable isotope internal standards and thereafter purified by ultrafiltration. The purified samples were analyzed by LC-MS/MS in the multiple reaction monitoring mode after separation on a multimode octa decyl silyl column. The coefficient of variation of free-MN and -NMN measurement was 7.6% and 5.5%, respectively. The linearity range was 0.5-10 mu g/l for both analytes. Degradation was less than 10% for both analytes under any of the storage conditions. The median free-NMN ratio to creatinine of 9 PC dogs (595, range 144-47,961) was significantly higher (P< 0.05) than that of 13 dogs with hypercortisolism (125, range 52-224) or 15 healthy dogs (85, range 50-117). The developed method is simple and may not require acidification of spot urine. The results of this preliminary retrospective study suggest that the measurement of urinary free metanephrines is a promising tool for diagnosing canine PC.公益社団法人 日本獣医学会 (The Japanese Society of Veterinary Science)Journal Articlehttp://hdl.handle.net/2115/826690916-7250Journal of veterinary medical science8346486552021-05-05enginfo:doi/10.1292/jvms.20-0508none