Abstract
The cascade of adenosine 5'-monophosphate-activated protein kinase (AMPK) is known to be a sensor of cellular energy charge. In this context, a paradigm for obesity treatment via the activation of AMPK has attracted the suppliers of complementary medicines and supplements. It is possible that products that increase the concentration of adenosine 5'-monophosphate (AMP) in the body would be efficacious in reducing body weight. However, since there is currently little information concerning the toxicity of AMP, the cytotoxic action of AMP on rat thymocytes was examined by flow cytometry. Incubation of cells with AMP at a concentration of 30 μM or more for 24 hr significantly increased the populations of dead cells, shrunken cells, and cells containing hypodiploidal DNA in a concentration-dependent manner. Z-VAD-FMK, a pan-inhibitor of caspases, attenuated the AMP-induced changes in cell populations. It is concluded that AMP at a concentration of 30 μM or more exerts a cytotoxic action, which is dependent on the activation of caspases.
