TY - JOUR T1 - Dual effects of angiotensin II on calcium currents in neonatal rat nodose neurons JF - The Journal of Neuroscience JO - J. Neurosci. SP - 7159 LP - 7167 DO - 10.1523/JNEUROSCI.14-11-07159.1994 VL - 14 IS - 11 AU - K Bacal AU - DL Kunze Y1 - 1994/11/01 UR - http://www.jneurosci.org/content/14/11/7159.abstract N2 - Angiotensin II (AII) reversibly modulates calcium current in isolated neonatal rat nodose ganglion cells by two different pathways. A maximum inhibitory effect of 43 +/- 6% (n = 25) of the peak calcium current at - 10 mV was observed at 10 nM AII. The IC50 of the inhibitory response was 100 pM. Losartan, a specific antagonist for the AT1 type of AII receptor, abolished the AII-induced inhibition, as did preincubation with pertussis toxin (PTX). When omega-conotoxin GVIA (CTX) was added to the bath solution, AII produced no inhibition of the remaining calcium current, indicating that the AII inhibition was mediated through CTX-sensitive calcium channels. Reversible facilitation of calcium current was seen more rarely. The AII-induced facilitation was unaffected by losartan and PTX, indicating that the effect is mediated by a non-AT1 receptor and does not depend upon a PTX-sensitive G- protein. The facilitation is present when the CTX-sensitive current has been blocked and involves activation of a reserve pool of dihydropyridine (DHP)-sensitive channels. In general, a particular neuron exhibited either inhibition or facilitation. However, in some neurons both inhibition and facilitation could be demonstrated in the presence of the appropriate blocking agents. ER -