A. Forsby et E. Walum, POLYGODIAL INDUCES INOSITOL PHOSPHATE TURNOVER IN HUMAN NEUROBLASTOMASH-SY5Y CELLS, Neuroscience letters, 217(1), 1996, pp. 50-54
The pungent sesquiterpenoid unsaturated dialdehydes polygodial and iso
velleral, have previously been shown to increase the intracellular fre
e calcium concentration [Ca2+](i) in human neuroblastoma SH-SY5Y cells
, partly by a release from intracellular Ca2+ stores, whereas the non-
pungent compound epipolygodial, had no effect on the [Ca2+](i). In thi
s study, we investigated the effect of isovelleral, polygodial and epi
polygodial on inositol phosphate (IP) formation on the assumption that
there might be a correlation between the release of intracellular Ca2
+ and pungency of the compounds. It was found that polygodial induced
IP mobilization in a concentration dependent way, whereas isovelleral
had no effect on the IP formation in the SH-SY5Y cells. Phosphoinositi
de (PPI) turnover was activated by epipolygodial, but only at concentr
ations 40-fold higher than for polygodial, which emphasizes the import
ance of the correct stereometry in the dialdehyde configuration for th
e biological activity of polygodial. The polygodial-induced formation
of IP1 was reduced by 71% under extracellular calcium-free conditions,
which suggests feedback interactions between the IP formation and the
increase in [Ca2+](i) to account for a periodic activation of phospho
lipase C (PLC).