Gymnopilin-a substance produced by the hallucinogenic mushroom, Gymnopilus junonius-mobilizes intracellular Ca²⁺ in dorsal root ganglion cells

抄録

Gymnopilus junonius is a widely spread mushroom in Japan and well known as a hallucinogenic mushroom. Gymnopilin was purified from the fruiting body of G. junonius and was reported to act on the spinal cord and depolarize motoneurons. This is the only evidence that gymnopilin has a biological effect on animals and no mechanism of the action has been determined at all. In this study, we examined effects of gymnopilin on intracellular Ca²⁺ concentrations ([Ca²⁺]_i) of cultured cells isolated from the dorsal root ganglion (DRG) of the rat. The cell culture consisted of neurons and non-neuronal cells. Gymnopilin increased [Ca²⁺]_i in both the types of cells. The gymnopilinevoked [Ca²⁺]_i rise in the non-neuronal cells was inhibited by cyclopiazonic acid and U-73122, inhibitors of Ca²⁺-ATPase of the intracellular Ca²⁺ store and phospholipase C, respectively, but not by removal of extracellular Ca²⁺. These results indicate that gymnopilin activated phospholipase C and mobilize Ca²⁺ from the intracellular Ca²⁺ store in non-neuronal cells from the DRG. This is the first report to show that gymnopilin directly acts on cells isolated from the mammalian nervous system.