Electrical and Thermal Modulation of Protein Synthesis in Cartilage: A Model for Field Effects on Biological Tissues

摘要

The possibility that applied electric fields may alter physiological function has been examined using articular cartilage as an experimental model. Field-induced changes in stress protein and total protein synthesis have been quantified. The amplitudes and frequencies of the applied fields were motivated by the values associated with naturally occurring fields, and by some models of possible mechanisms of interaction. Cartilage specimens were exposed to current densities up to 30 milliamp/cm squared, at frequencies of 1, 10, and 100 Hz and 1 and 10 kHz for 12 hours in a chamber filled with media containing 35S-methionine. Unstimulated controls were incubated and labelled in an identical specimen chamber in the same incubator. Stress protein synthesis was assessed by examination of gel fluorographs. Total protein synthesis was assessed by radiolabel incorporation. The finding that relatively large current densities were required to measurably increase protein synthesis does not necessarily indicate that physiological current densities are unimportant. The change in total protein synthesis indicates that electric fields may plat a role in physiological regulation of chondrocyte metabolism. These results may have important implications regarding clinical applications of fields to alter growth and remodeling.