Calcium confusion - is the variability in calcium response by Sertoli cells to specific hormones meaningful or simply redundant?

When results of more than ten different studies on hormone-induced calcium signals in Sertoli cells are taken together, a wide variety of responses em erges. The reported changes range from increased concentrations, via no res ponse 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, err atic variations in response are also observed within research groups under very similar experimental conditions. Such 'negative' findings are mainly r eported orally and do not further penetrate the scientific community. As ho rmone-dependent calcium responses evidently may depend very much on the con text of the cells, calcium transients would appear to be unreliable bioassa y principles with which to detect the primary actions of FSH and effecters such as androgens on Sertoli cells. A more important biological question is whether these sometimes opposed calcium transients are connected with a pa rticular cellular response. To date there is no evidence for such a tight c oupling in Sertoli cells, implying that, at least under in vitro conditions , calcium signals might even be redundant altogether. Such calcium variabil ity 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 cal cium language.