Biochemical interactions of low frequency pulsing electromagnetic fields on melanoma cells

Electromagnetic field stimulation of melanoma cells can induce differentiation as monitored by tyrosinase activity in a manner similar to that observed with the normal physiological regulator, melanocyte stimulating hormone (MSH). Short-term exposure depresses cAMP and cAMP-dependent protein kinase (PKA) levels for up to 30 minutes. In addition, when PEMF is removed there is a rapid increase in cAMP and PKA levels. The increase appears to be the trigger for induction of differentiation. Results obtained with pertussis toxin indicate that the site of interaction of PEMF may be at the level of the GTP binding proteins which regulate the receptor-adenylate-cyclase complex.<>