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Aim:To investigate the effect of aluminum(Al)on high voltage-dependent cal-cium current(I_(HVA))and its modulation by ginkgolide B(Gin B).Methods:Thewhole-cell,patch-clamp technique was used to record I_(HVA)from acutely isolatedhippocampal CA1 pyramydal neurons in rats.Results:A1 0.1 mmol/L(lowconcentration)reduced I_(HVA);A1 0.75 and 1.0 mmol/L(high concentrations)in-creased I_(HVA),and Al decreased and increased I_(HVA)at intermediate concentrationsof 0.25 and 0.5 mmol/L.The increase of I_(HVA)by Al 1.0 mmol/L was enhanced by theadenylyl cyclase(AC)agonist forskolin and was partly abolished by the cyclicadenosine monophosphate(cAMP)-dependent protein kinase A(PKA)antago-nist H-89,whereas the decrease observed with Al 0.1 mmol/L was neither reversedby forskolin nor affected by H-89.Gin B had no effect on I_(HVA)in normal neurons,but canceled the increase in I_(HVA)by 1.0 mmol/L Al.Conclusion:The resultsindicate that the mechanism of Al affecting I_(HVA)differs at different concentrations,and this may be attributed to its complex actions.Gin B could prevent neuronsfrom injury by inhibiting calcium influx.
Aim: To investigate the effect of aluminum(Al)on high voltage-dependent cal-cium current(I_(HVA)) and its modulation by ginkgolide B(Gin B).Methods:Thewhole-cell,patch-clamp technique was used to Record I_(HVA) from acutely isolated hippocampal CA1 pyramydal neurons in rats.Results: A1 0.1 mmol/L(low concentration) reduced I_(HVA); A1 0.75 and 1.0 mmol/L(high concentrations) in-creased I_(HVA),and Al decreased and increased I_(HVA)at intermediate concentrations of 0.25 and 0.5 mmol/L.The increase of I_(HVA) by Al 1.0 mmol/L was enhanced by the adenyllyl cyclase(AC)agonist forskolin and was partly abolished by the cyclicadenosine monophosphate ( cAMP)-dependent protein kinase A (PKA) antago-nist H-89, whereas the decreased observed with Al 0.1 mmol/L was about reversedby forskolin nor affected by H-89. Gin B had no effect on I_(HVA) in normal Neurons, but canceled the increase in I_(HVA) by 1.0 mmol/L Al.Conclusion:The resultsindicate that the mechanism of Al affecting I_(HVA)differs at different concentrat The ions, and this may be attributed to its complex actions.Gin B could prevent neurons from injury by inhibiting calcium influx.