Fig. 3.

DOR-mediated cellular and molecular regulation in prolonged hypoxia/ischemia. ROS reactive oxygen species or oxygen free radicals, HPC hypoxic pre-conditioning, HIF hypoxia inducible factor, EO endogenous opioids, SOD superoxide dismutase, MPTP mitochondrial permeability transition pore. Arrows in red indicate effect of hypoxic/ischemic effects; dashed lines indicate inhibition; and green arrows/lines indicate the survival or neuroprotective mechanisms or changes. Blue ovals represent components involved in the neuroprotective pathways while red hexagons represent components playing role in the hypoxic/ischemic cell injury