Impact of gadodiamide (Omniscan) on a beef liver catalase ex vivo model

Gadolinium is used in Magnetic Resonance Imaging scans to enhance image quality and allow doctors to more effectively diagnose patients. It is administered to patients through intravenous injection of gadolinium-based contrast agents (GBCAs). Although most of the injected gadolinium is excreted from the body soon after it is administered, studies have shown that some gadolinium remains in the body for extended periods of time. In patients with renal dysfunction, gadolinium retention has been associated with Nephrogenic Systemic Fibrosis, and even in patients with normal kidney function, long-term gadolinium deposits have been observed in the brain following exposure to GBCAs. The specific biochemical effects of gadolinium retention remain largely unknown, but it is possible that gadolinium may impact enzymatic activity. The present experiment investigated the effects of gadodiamide (brand name Omniscan), a common GBCA, on the function of catalase, a crucial biological enzyme that converts hydrogen peroxide into water and oxygen. We exposed beef liver to various concentrations of hydrogen peroxide both with and without gadodiamide, and we determined the V_max and K_m values of the catalase. We found that the presence of gadodiamide did not significantly inhibit catalase, which we hypothesize is due to the chelating agent present in gadodiamide. This work has important implications for understanding the biochemical effects of GBCAs and their potential impact on patient health.