Calcium confusion--is the variability in calcium response by Sertoli cells to specific hormones meaningful or simply redundant?
Journal of Endocrinology. ISSN 0022-0795.
Rommerts, F.F.G. (Focko); Lyng, F.M.; Ledebur, von E.; Quinlan, L.; Jones, G.R.; Warchol, J.B.; Stefanini, M. (Miria); Ravindranath, N.; Joffre, M.
When results of more than ten different studies on hormone-induced calcium
signals in Sertoli cells are taken together, a wide variety of responses
emerges. The reported changes range from increased concentrations, via no
response at all, to decreased calcium concentrations. Minor variations in
cell isolation techniques, culture conditions, or techniques for measuring
the intracellular calcium could explain some of these differences.
However, erratic variations in response are also observed within research
groups under very similar experimental conditions. Such 'negative'
findings are mainly reported orally and do not further penetrate the
scientific community. As hormone-dependent calcium responses evidently may
depend very much on the context of the cells, calcium transients would
appear to be unreliable bioassay principles with which to detect the
primary actions of FSH and effectors such as androgens on Sertoli cells. A
more important biological question is whether these sometimes opposed
calcium transients are connected with a particular cellular response. To
date there is no evidence for such a tight coupling in Sertoli cells,
implying that, at least under in vitro conditions, calcium signals might
even be redundant altogether. Such calcium variability is probably not
unique to Sertoli cells, and the aim of this commentary is to promote an
open debate that may help to transform the current state of 'calcium
confusion' into a better understanding of the intracellular calcium