RADIATION DAMAGE IN MUSCLE CELL MEMBRANES AND REGULATION OF CELL METABOLISM
Abstract
Effects of 100,000r doses on striated frog muscles include prolonged relaxation time, more rapid fatigue, and decreased ATP and glycogen content, but increased potassium and sodium effluxes, sodium influx and oxygen consumption, compared with non-irradiated controls. Twitch latency and rise time are not changed. Magnesium-ACTIVATED ATPase activity of homogenates or mitochondrial suspensions decreases immediately after irradiation, but increases with time more rapidly than in controls. Biochemical findings suggest uncoupling of oxidative phosphorylation; ion flux data suggest increased membrane permeability. This leads to the hypothesis that irradiation results in sarcoplasma membrane damage, thereby increasing ion permeabilities, and mitochondrial structure damage, thereby interfering with oxidative hosphorylation and reducing ATP production. A 90% decrease in membrane potential during irradiation has already been reported. The observed increases in Na and K fluxes after irradiation explain these findings. At these radiation levels, our data do not require any hypothesis of early direct damage to the contractile mechanism per se.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1962
- Accession Number
- AD0296449
Entities
People
- Adolfo Portela
- Juan Carlos Perez
Organizations
- Emory University