a mechanism for the transfer of reducing equivalents from the cytosol into the mitochondria; NADH is used to synthesize glycerol 3-phosphate in the cytosol; this compound is then transported into the mitochondria where it is converted to dihydroxyacetone phosphate (DHAP) using FAD; DHAP then returns to the cytosol to complete the cycle; found in brain tissue, brown adipose tissue, and white muscle.
