>Have you examined the role of calcium in this model? What about other cellular models to examine this effect?
Dear Dr. Tan,
Melatonin was shown to bind only to the calcium/calmodulin complex and not to calmodulin alone (Brain Res (1991) 557: 289-292; Biochim Biophys Acta (1996) 1290: 191-196).
We only investigated a possible calmodulin antagonism of melatonin in Jurkat cells and human peripheral blood lymphocytes, but, since calmodulin is a ubiquitous intracellular protein and melatonin easily can diffuse across cell membranes, their possible interaction should be in the same manner also in different cell types.