Simultaneous measurement of intracellular Ca2+ and asynchronous transmitter release from the same crayfish bouton.
AUTOR(ES)
Ravin, R
RESUMO
1. A technique has been developed to monitor neurotransmitter release simultaneously with intracellular Ca2+ concentration ([Ca2+]i) in single release boutons whose diameters range from 3 to 5 microns. 2. Using this technique, we have found a highly non-linear relationship between the rate of asynchronous release and [Ca2+]i. The Hill coefficient lies between 3 and 4. 3. The affinity (Kd) of the putative release-related Ca2+ receptor for asynchronous release was calculated to be in the range of 2-4 microM. 4. The same range of values of Hill coefficient and Kd were obtained when [Ca2+]i was elevated both by bath application of ionomycin and by repetitive stimulation at high frequency. 5. Our results show that the Ca2+ receptor(s) associated with asynchronous release exhibits high affinity for Ca2+.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1159474Documentos Relacionados
- P-type Ca2+ channels mediate excitatory and inhibitory synaptic transmitter release in crayfish muscle.
- Interactions between intracellular Ca2+ stores: Ca2+ released from the NAADP pool potentiates cADPR-induced Ca2+ release
- Ca2+ and Sr2+ entry induced Ca2+ release from the intracellular Ca2+ store in smooth muscle cells of rat portal vein.
- Release of Ca2+ by noradrenaline and ATP from the same Ca2+ store sensitive to both InsP3 and Ca2+ in rat portal vein myocytes.
- Activation of neurohypophysial vasopressin release by Ca2+ influx and intracellular Ca2+ accumulation in the rat.