Golgi apparatus is involved in intracellular calcium regulation in
epithelial llc-pk1 cells.
Zha, Xiaohui, Subhash Chandra, Andrew J. Ridsdale, and George H. Morrison.
Department of Chemistry, Cornell University, Ithaca, NY 14853-1301, Tel.
(607)-255-3614, Fax (607)-255-9930
APStracts 2:0037C, 1995.
Several lines of evidence suggest that the Golgi apparatus is involved in
calcium regulation in renal epithelial LLC-PK1 cells. Laser scanning confocal
microscopy (LSCM) was employed to establish that a prominent perinuclear
region is occupied mainly by the Golgi apparatus in this cell line. LSCM
measurements in individual cells with the ionized Ca2+ indicator calcium
green revealed that stimulation of LLC-PK1 cells with arginine vasopressin
(AVP) resulted in the elevation of ionized Ca2+ levels. However, the
vasopressin-induced rise in ionized Ca2+ was attenuated if the Golgi
apparatus was disassembled by pretreating the cells with brefeldin A (BFA).
Subcellular measurements of total calcium with ion microscopy in
cryogenically prepared cells indicated that (i) within one minute of AVP
treatment significant quantities of sequestered calcium were released from
the perinuclear Golgi region and (ii) the BFA treatment reduced the total
calcium stored in the Golgi region. These observations indicate that the
Golgi apparatus is sensitive to hormonal stimulation and may play important
roles in intracellular calcium regulation in LLC-PK1 cells.
Received 19 September 1994; accepted in final form 18 November 1994
APS Manuscript Number C0561-4.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1994 The American Physiological Society.
Published in APStracts on 27 February 1995.