Puromycin: Action on Neuronal Mitochondria
Pierluigi Gambetti 1,
Nicholas K. Gonatas 1, and
Louis B. Flexner 2
1 Departments of Pathology and Neurology, Hospital of University of Pennsylvania, Philadelphia 19104
2 Department of Anatomy, University of Pennsylvania School of Medicine
Puromycin, in dosages that inhibit cerebral protein synthesis and expression of memory in mice, produces swelling of neuronal mitochondria. Acetoxycycloheximide, which inhibits cerebral protein synthesis to the same extent as puromycin, fails to produce swelling of neuronal mitochondria. Puromycin and heximide mixtures produce severe inhibition of protein synthesis, but result in a minimal swelling of neuronal mitochondria and in a decrease of peptidylpuromycin complexes to a level of 30 percent of that following the injection of puromycin alone. It is concluded that swelling of neuronal mitochondria in the presence of puromycin is not due to inhibition of cerebral protein synthesis per se, but is related to a specific action of puromycin on ribosomal protein synthesis. The findings are consistent with the hypothesis that peptidyl-puromycin complexes are responsible for mitochondrial swelling.
