Bacolod MD et al. - The rate of release of the cations was higher in pH 7.4 than at pH 7.0, which is likely a result of more rapid decomposition of BCNU (thus faster release of MT-binding intermediate) at pH 7.4 than at pH 7.0. The authors demonstrate that resistance to BCNU may be a result of elevated levels of MTs which act by sequestering the drug's decomposition product(s).