The occupancy of L-type Ca2+ channels by treatment with an oral dose of the dihydropyridine-type Ca2+ antagonist nicardipine (sustained-release formulation) was evaluated in membrane preparations of rat frontal cortex and hippocampus using a radioligand binding assay technique, with [3H]-nicardipine as a ligand. Three hours after nicardipine administration, specific binding was decreased by about 15-20%, both in the frontal cortex and hippocampus. This indicates that oral nicardipine occupied approximately 15-20% of L-type Ca2+ channels. A progressive occupancy of Ca2+ channels was observed between six and 12 h after nicardipine administration. Twelve hours after drug administration, approximately 65-70% of Ca2+ channels were occupied. These findings indicate that oral treatment with 3 mg/kg of nicardipine (sustained-release formulation) occupies L-type Ca2+ channels in rat brain by more than 40% from the 6th to the 24th h after drug administration. This suggests that an oral dose of nicardipine (sustained-release formulation) in duces a significant occupancy of L-type Ca2+ channels in rat frontal cortex and hippocampus for about one day. The possible clinico-therapeutic relevance of this observation is discussed.

Occupancy by oral administration of nicardipine of L-type calcium channels in rat brain

AMENTA, Francesco;TOMASSONI, Daniele;TAYEBATI, Seyed Khosrow;
2001

Abstract

The occupancy of L-type Ca2+ channels by treatment with an oral dose of the dihydropyridine-type Ca2+ antagonist nicardipine (sustained-release formulation) was evaluated in membrane preparations of rat frontal cortex and hippocampus using a radioligand binding assay technique, with [3H]-nicardipine as a ligand. Three hours after nicardipine administration, specific binding was decreased by about 15-20%, both in the frontal cortex and hippocampus. This indicates that oral nicardipine occupied approximately 15-20% of L-type Ca2+ channels. A progressive occupancy of Ca2+ channels was observed between six and 12 h after nicardipine administration. Twelve hours after drug administration, approximately 65-70% of Ca2+ channels were occupied. These findings indicate that oral treatment with 3 mg/kg of nicardipine (sustained-release formulation) occupies L-type Ca2+ channels in rat brain by more than 40% from the 6th to the 24th h after drug administration. This suggests that an oral dose of nicardipine (sustained-release formulation) in duces a significant occupancy of L-type Ca2+ channels in rat frontal cortex and hippocampus for about one day. The possible clinico-therapeutic relevance of this observation is discussed.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11581/117227
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact