Maitotoxin stimulates phosphoinositide breakdown in neuroblastoma hybrid NCB-20 cells.

Abstract

1. Maitotoxin (MTX) was an extraordinarily potent stimulant of phosphoinositide breakdown in the neuroblastoma hybrid NCB-20 cells. 2. Maximal responses were obtained at 0.25-0.5 ng MTX/ml, and resulted in increased formation of [3H]inositol mono-, bis-, and trisphosphates. Increased formation of [3H]inositol bis- and trisphosphate was observed as early as 15 sec after the addition of MTX. 3. MTX-induced phosphoinositide breakdown in NCB-20 cells was not antagonized by organic (nifedipine, methoxyverapamil) or inorganic (Mn2+, Co2+, Cd2+) calcium channel blockers. However, the response on phosphoinositide breakdown was completely eliminated in the absence of extracellular calcium. 4. The results suggest that MTX either directly stimulates phosphoinositide breakdown in a calcium-dependent manner or acts indirectly through calcium channels insensitive to organic/inorganic calcium channel blockers.

• Authors: F Gusovsky, T Yasumoto, J W Daly
• Journal: Cellular and molecular neurobiology (Cell Mol Neurobiol) Vol. 7 Issue 3 Pg. 317-22 (Sep 1987) ISSN: 0272-4340 [Print] United States
• PMID: 2449966 (Publication Type: Journal Article)

Chemical References

• Calcium Channel Blockers
• Ion Channels
• Marine Toxins
• Oxocins
• Phosphatidylinositols
• maitotoxin
• Calcium

Topics

• Animals
• Calcium (metabolism)
• Calcium Channel Blockers (pharmacology)
• Cricetinae
• Hybrid Cells (drug effects, metabolism)
• Ion Channels (drug effects, metabolism)
• Marine Toxins (pharmacology)
• Mice
• Neuroblastoma (metabolism)
• Oxocins
• Phosphatidylinositols (metabolism)
• Tumor Cells, Cultured (drug effects, metabolism)