Abstract
The results presented demonstrate that in D neurons of the snail Helix pomatia L., acetylcholine (ACh) (10 ÷ 100 μM) and sertonin (5-HT) (0.1 ÷ 1000 μM) applications reduce both the basal intracellular concentration level ([Ca2+]in) and the amplitudes of calcium transients induced by membrane depolatrization. It is likely that the mechanism of [Ca2+]in changes is the suppression of calcium inward currents (ICa). Influence of Ach and 5-HT on ICa were studied. Both effects were dose-dependent (ACh-0.01 ÷ μM and 5-HT-0.1 ÷ 1000 μM). The half-maximal effects (IC50) were evoked by Ah concentration of 0.15 μM and 5-HT-15 μM. Furthermore we have also shown that in some cells 5-HT could evoke a transient increase in ICa (IC50 = 2 μM. The effects of Ach abd 5-HT were nonadditive-the subsequent application of ACh after 5-HT, and vice versa, produced no inhibitory effects. This may indicate that both substances act through a common inermediate (possibly, G-protein).
Original language | English |
---|---|
Pages (from-to) | 551-559 |
Number of pages | 9 |
Journal | Cellular Signalling |
Volume | 6 |
Issue number | 5 |
DOIs | |
State | Published - Jul 1994 |
Keywords
- G-proteins
- Serotonin, acetylcholine
- cAMP
- calcium fluxes
- intracellular calcium
- ionic currents
- molluscan identified neuron