 There have been many suggestions to what this might be, the sarcolemmal ATP-sensitive potassium channel, the mitochondrial ATP-sensitive potassium channel, the mitochondrial permeability transition pore, reactive oxygen species generation, chloride channels, the inward rectifier potassium ion channel and connexon 43 related channels.It has also been shown that the protective effect of IPC is suppressed by pathological conditions such as hypercholesterolemia, hyperglycemia, hypertension, cardiac hypertrophy, aging, obesity and hyperhomocysteinemia.The only group of humans who are chronically exposed to an opioid with delta activity are methadone maintained patients treated for chronic pain or opioid addiction.