oligomycins and indo-1

The effects of mitochondrial uncoupling on the calcium homeostasis of prostatic cells were investigated using the prostatic cancer cell line LNCaP and indo-1 spectrofluorimetry. Carbonyl cyanide m-chloro-phenylhydrazone (CCCP) was used as uncoupler. Resting LNCaP cells responded to CCCP by a biphasic increase in [Ca2+]i. The first phase of increase which corresponded to the release of a mitochondrial CCCP-sensitive Ca2+ store was followed by a second increase phase consisting of Ca2+ influx through the plasma membrane. The relationship between the CCCP- and the InsP3-sensitive stores was investigated using thapsigargin (TG). The release part of the Ca2+ response to TG was reduced in a time-dependent manner by previous exposure of the cells to CCCP, suggesting that CCCP also acts on non-mitochondrial stores. Our results show that CCCP releases Ca2+ from both mitochondrial and non-mitochondrial stores in prostatic cells. The possible mechanisms of these effects are discussed.

Topics: Adenosine Triphosphate; Antimycin A; Calcium; Carbonyl Cyanide m-Chlorophenyl Hydrazone; Cell Membrane; Enzyme Inhibitors; Fluorescent Dyes; Humans; Indoles; Male; Mitochondria; Oligomycins; Prostatic Neoplasms; Spectrometry, Fluorescence; Thapsigargin; Time Factors; Tumor Cells, Cultured; Uncoupling Agents