Title : Co-localisation of functional nicotinic and ionotropic nucleotide receptors in isolated cholinergic synaptic terminals - Diaz-Hernandez_2002_Neuropharmacol_42_20 |
Author(s) : Diaz-Hernandez M , Pintor J , Castro E , Miras-Portugal MT |
Ref : Neuropharmacology , 42 :20 , 2002 |
Abstract :
The combination of immunological and microfluorimetric techniques has permitted the identification and analysis of the Ca2+ influx responses in single rat midbrain cholinergic terminals. These terminals represent 22% of the total synaptosomal population and about 63% of them responded to nucleotides by a Ca2+ influx. The nucleotide response distribution in cholinergic synaptic terminals is as follows; 22.4% to diadenosine pentaphosphate (Ap5A), 24.7% to adenosine 5'-triphosphate (ATP) and 16.3% to both agonists. The ATP and Ap5A are able to induce acetylcholine release in a dose- and calcium-dependent way, being the EC50 values 0.22+/-0.1 microM and 1.5+/-0.1 microM respectively. Specific inhibitors can block this secretory effect. The studies of Ca2+ influx responses in isolated single synaptic terminals have also permitted to demonstrate the wide co-expression of functional nicotinic and nucleotidic receptors. The percentage values of the terminals responding to both ATP/nicotine and Ap5A/nicotine were 18.4% and 19.1%, respectively, considering the total population. Immunological studies also confirmed the presence of P2X3 subunits and alpha4 and alpha7 nicotinic receptor subunits in about 36%, 30% and 20%, respectively, of the cholinergic terminals. |
PubMedSearch : Diaz-Hernandez_2002_Neuropharmacol_42_20 |
PubMedID: 11750913 |
Diaz-Hernandez M, Pintor J, Castro E, Miras-Portugal MT (2002)
Co-localisation of functional nicotinic and ionotropic nucleotide receptors in isolated cholinergic synaptic terminals
Neuropharmacology
42 :20
Diaz-Hernandez M, Pintor J, Castro E, Miras-Portugal MT (2002)
Neuropharmacology
42 :20