Quantification of Cardiotonic Steroids Potentially Regulated by Paraoxonase 3 in a Rat Model of Chronic Kidney Disease Using UHPLC-Orbitrap-MS.Endogenous cardiotonic steroids (CTSs), such as telocinobufagin (TCB) and marinobufagin (MBG) contain a lactone moiety critical to their binding and signaling through the Na+/K+-ATPase.  TCB and MBG were extracted from rat urine samples, and the analyses were carried out using ultra-high pressure liquid chromatography-Orbitrap-mass spectrometry (UHPLC-Orbitrap-MS). 
UHPLC-Orbitrap-MS