Identification and Functional Distribution of Intracellular Ca2+ Channels in Mouse Lacrimal Gland Acinar Cells
W.E Medina-Ortiz, E.V Gregg, A.M Brun-Zinkernagel, P Koulen*
Identifiers and Pagination:Year: 2007
First Page: 8
Last Page: 16
Publisher Id: TOOPHTJ-1-8
Article History:Received Date: 23/10/2007
Revision Received Date: 14/11/2007
Acceptance Date: 16/11/2007
Electronic publication date: 4/12/2007
Collection year: 2007
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.5/) which permits unrestrictive use, distribution, and reproduction in any medium, provided the original work is properly cited.
We have determined the presence and cellular distribution of intracellular calcium channels, inositol 1, 4, 5-trisphosphate receptors (IP3Rs) and ryanodine receptors (RyRs) in adult and postnatal (P10) lacrimal gland acinar cells. Western blot analysis of both P10 cultures and adult tissue identified the presence of each IP3R and RyR isotypes. The immunocytochemistry analysis showed a differential cellular distribution of these calcium channels where the nuclear envelope, endoplasmic reticulum (ER) and Golgi apparatus membranes represent areas with highest levels of channel expression. This IP3R and RyR isotype distribution is confirmed by the immuno-EM results. The findings described in this study are in agreement with published pharmacological data that shows the participation of these channels in the secretion process of the lacrimal gland acinar cells. Furthermore, the differential subcellular distribution between the isoforms could indicate a potential role of these intracellular Ca2+ channels on the regulation of specific cellular functions.