HBO and the uptake and retention of [¹²⁵I] MTBG in human platelets and two neuroendocrine cell lines

In this paper we report the effects of Hyperbaric Oxygen (HBO) exposure on the uptake and retention of meta-iodobenzylguanidine (MIBG) in human platelets and two neuroendocrine cell lines. The combination of [¹³¹I] MIBG and HBO is used for therapy of neuroblastoma. Exposure to HBO can cause oxidative stress, which is potentially capable of affecting uptake and storage of MIBG in both neuroendocrine cells and platelets. Oxidative stress generated by menadione decreased both the uptake and retention of MIBG in the platelets and the cell lines. HBO did not affect these processes, indicating that the HBO induced oxidative stress is not high enough to affect the MIBG uptake and storage pathways in these cells. This suggests that the positive effects observed by the treatment of neuroblastoma patients with the combination of HBO and [¹³¹I] MIBG are most likely not due to improved uptake or retention of MIBG in the neuroblastoma. Neither can reduced cytotoxicity (trombocytopenia) be expected due to decreased uptake/retention of [¹³¹I] MIBG in platelets or their precursor cells.