SCIENCEscience.org 3 DECEMBER 2021¥VOL 374 ISSUE 6572 1233
Fig. 4. Fumarate reduction supports mitochondrial functions in tissues
capable of net reversal of the SDH reaction.(A) Depiction of the workflow for
the in vivo^13 C 515 N 2 -glutamine stable isotope tracing experiment to measure
the net directionality of the SDH complex in tissues. (B) In vivo stable isotope
tracing of^13 C 515 N 2 -glutamine in indicated tissues. Mice were euthanized
20 min after retroorbital and intraperitoneal injections. Succinate oxidation was
calculated as the ratio of picomoles fumarate M + 4 to picomoles succinate
M + 4. Fumarate reduction was calculated as the ratio of picomoles succinateRESEARCH | RESEARCH ARTICLES