Cholecystokinin analog JMV-180-induced intracellular calcium oscillations are mediated by inositol 1,4,5-trisphosphate in rat pancreatic acini.
OBJECTIVE
To investigate whether inositol 1,4,5-trisphosphate (IP3) is involved in secretory response of pancreatic acini to cholecystokinin (CCK) analog Boc-Tyr (SO3H)-Nle-Gly-Trp-Nle-Asp-2-phenylethylester.2NH3 (JMV-180).


METHODS
Dynamics of cytosolic Ca2+ concentration, [Ca2+]c, was recorded by ratiometry of Fura-2 in pancreatic acini.


RESULTS
In perfused preparations of isolated rat pancreatic acinar cells, 2-aminoethoxydiphenylborate (2APB), a new membrane permeant inhibitory modulator of IP3-mediated calcium release from internal stores, inhibited JMV-180-induced [Ca2+]c spikes, and 2APB at 100 mumol.L-1 resulted in an immediate, complete inhibition of the spikes.


CONCLUSIONS
Recurrent [Ca2+]c spikes induced by continuous stimulation with JMV-180 are initiated via IP3-mediated Ca2+ release from internal Ca2+ stores.
Cui
Z J
ZJ
Institute of Cell Biology, Beijing Normal University, Beijing 100875, China. zjcui@bnu.edu.cn
Kanno
T
T
D000818:Animals; D001896:Boron Compounds / Q000494:pharmacology*; D015220:Calcium Channels; D020013:Calcium Signaling / Q000187:drug effects*; D002469:Cell Separation; D005260:Female; D015544:Inositol 1,4,5-Trisphosphate / Q000037:antagonists & inhibitors / Q000502:physiology*; D053496:Inositol 1,4,5-Trisphosphate Receptors; D008297:Male; D010179:Pancreas / Q000166:cytology / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018160:Receptors, Cytoplasmic and Nuclear / Q000037:antagonists & inhibitors; D012844:Sincalide / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors*
D001896:Boron Compounds; D015220:Calcium Channels; D053496:Inositol 1,4,5-Trisphosphate Receptors; D018160:Receptors, Cytoplasmic and Nuclear; C058451:JMV 180; D015544:Inositol 1,4,5-Trisphosphate; C109986:2-aminoethoxydiphenyl borate; D012844:Sincalide