Mitochondrial calcium uptake and oxygen consumption in cystic fibrosis.

Reports of exocrine gland secretory anomalies in cystic fibrosis and increased calcium 
ion concentrations in some CF secretions and the importance of cellular 
Ca to stimulus-secretion coupling led us to study cellular Ca in 
CF. We report data on Ca uptake studies with mitochondrial and 
microsomal fractions isolated from skin fibroblasts of subjects with CF and 
age-, sex- and passage number-matched controls in which mitochondria from CF 
cells accumulated more Ca than those from control cells. We also 
describe subsequent studies which show increased mitochondrial electron transport activity, measured 
as oxygen uptake by whole cells, in cells from subjects with 
CF and obligate heterozygotes. One can hypothesise a mechanism to link 
the altered mitochondrial Ca in CF fibroblasts and the major signs 
associated with the disease. Data suggest that the electron transport system 
in CF and obligate heterozygote fibroblasts is more active than that 
in respective controls, in the conditions of this study. The apparent 
central role of Ca in several pathogenetic pathways in CF and 
the data reported here in which both mitochondrial Ca capacity and 
oxygen consumption are increased in CF suggest that this organelle is 
a suitable focus for CF investigations. 