Formaldehyde suppresses neuronal apoptosis via inhibition of outward K(+) currents in rat hippocampus.

Formaldehyde (FA) is widely present in the environment, and is also a mammalian metabolite. However, its biological role has not been well understood. Here, we show that FA plays an anti-apoptotic role in cultured hippocampal neurons: FA suppressed staurosporine-induced neuronal apoptosis and inhibited the activity of apoptosis-associated caspase-3/7 proteases in a concentration-dependent manner. Moreover, FA suppressed outward K(+) currents and attenuated the enhanced IK currents that are associated with neuronal apoptosis. As an increase in outward K(+) currents is critical for cell apoptosis, our results suggest that FA exerts its anti-apoptotic effects on neuronal cells, probably through its inhibitory effect on the outward K(+) currents.