PT  - JOURNAL ARTICLE
AU  - K Bacal
AU  - DL Kunze
TI  - Dual effects of angiotensin II on calcium currents in neonatal rat nodose neurons
AID  - 10.1523/JNEUROSCI.14-11-07159.1994
DP  - 1994 Nov 01
TA  - The Journal of Neuroscience
PG  - 7159--7167
VI  - 14
IP  - 11
4099  - http://www.jneurosci.org/content/14/11/7159.short
4100  - http://www.jneurosci.org/content/14/11/7159.full
SO  - J. Neurosci.1994 Nov 01; 14
AB  - 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.