Xenon induces metaphase arrest in rat astrocytes

The use of xenon as an almost ideal anesthetic with very little side effect s is gaining clinical acceptance, yet its effects on the cellular level are still unclear. It affects intracellular Ca2+-homeostasis but up to now no cellular event or Ca2+-signaling system has been described to be specifical ly sensitive to xenon. Here we report for the first time a specific effect of xenon on astroglial cells not found with another volatile anesthetic, is oflurane, nor with helium nor with N-2: treatment of primary astroglial cel ls from embryonic rat brain with xenon induces, apart from a slight retarda tion of the cell cycle, a block at metaphase. Upon removal of xenon cells a rrested at metaphase complete their mitosis normally. Even under continuous exposure to xenon, cells can be rescued from metaphase arrest by a small a nd transient increase in intracellular Ca2+; cells enter anaphase despite t he presence of xenon and complete cell division, exhibiting normal rate of chromosome movement and normal chromosome separation. These results suggest that xenon interferes with some Ca2+-dependent regulatory system required for the metaphase-anaphase transition; taking into account its anesthetic e ffects, xenon may be also involved in the control of glia-mediated signalin g transfer.