Abstract
Reactive oxygen species (ROS) are essential cellular metabolites widely implicated in many diseases including cancer, inflammation, and cardiovascular and neurodegenerative disorders. Yet, ROS signaling remains poorly understood, and their measurements are a challenge due to high reactivity and instability. Here, we report the development of (13)C-thiourea as a probe to detect and measure H(2)O(2) dynamics with high sensitivity and spatiotemporal resolution using hyperpolarized (13)C magnetic resonance spectroscopic imaging. In particular, we show (13)C-thiourea to be highly polarizable and to possess a long spin-lattice relaxation time (T(1)), which enables real-time monitoring of ROS-mediated transformation. We also demonstrate that (13)C-thiourea reacts readily with H(2)O(2) to give chemically distinguishable products in vitro and validate their detection in vivo in a mouse liver. This study suggests that (13)C-thiourea is a promising agent for noninvasive detection of H(2)O(2) in vivo. More broadly, our findings outline a viable clinical application for H(2)O(2) detection in patients with a range of diseases.