AIM: To observe the effects of methylflavonolamine (MFA) on free intracellular calcium concentration ([Ca2+](i)) of isolated embryonic rat brain cells in presence and absence of high extracellular potassium and L- glutamate. METHODS: [Ca2+](i) was measured in a spectrofluorophotometer by preloading the cells with calcium sensitive fluorescent indicator Fura 2-AM. RESULTS: Resting [Ca2+](i) was 197 ± 20 nmol · L-1 (n = 44) in the presence of Ca2+ 1.3 mmol · L-1 in Hanks' solution. MFA 0.15 mmol · L- 1 had no effect on the resting [Ca2+](i). When extracellular Ca2+ was 1.3 mmol · L-1, MFA (0.03 - 0.3 mmol · L-1) concentration-dependently inhibited the [Ca2+](i) elevation induced by high extracellular potassium, with an IC50 value of 0.14 (95 % confidence limits: 0.05-0.42) mmol · L- 1. At higher concentration (0.15 - 0.30 mmol · L-1), MFA decreased L- glutamate-induced [Ca2+](i) elevation, with an IC50 of 0.20 (95 % confidence limits: 0.01-3.40) mmol · L-1. CONCLUSION: MFA inhibited Ca2+ influx through voltage-dependent calcium channel and, at higher concentration, through receptor-operated calcium channel in the embryonic rat brain cells.
|Original language||English (US)|
|Number of pages||4|
|Journal||Acta Pharmacologica Sinica|
|State||Published - Jul 1 1996|
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ASJC Scopus subject areas
- Pharmacology (medical)