RESUMO
We have determined the presence and cellular distribution of intracellular calcium channels, inositol 1, 4, 5-trisphosphate receptors (IP3Rs) and ryanodine receptors (RyRs) in adult and postnatal (P10) lacrimal gland acinar cells. Western blot analysis of both P10 cultures and adult tissue identified the presence of each IP(3)R and RyR isotypes. The immunocytochemistry analysis showed a differential cellular distribution of these calcium channels where the nuclear envelope, endoplasmic reticulum (ER) and Golgi apparatus membranes represent areas with highest levels of channel expression. This IP(3)R and RyR isotype distribution is confirmed by the immuno-EM results. The findings described in this study are in agreement with published pharmacological data that shows the participation of these channels in the secretion process of the lacrimal gland acinar cells. Furthermore, the differential subcellular distribution between the isoforms could indicate a potential role of these intracellular Ca(2+ )channels on the regulation of specific cellular functions.
RESUMO
RT-PCR analysis of NPY mRNA expression in chick embryonic sympathoadrenal cells in culture showed that NGF increases sympathetic but not adrenal NPY mRNA content. These results show that the previously reported differential effect at the protein level can also be detected at the mRNA level, suggesting a pre-translational point of regulation. The differential NGF effect in such closely related phenotypes is particularly relevant to studies of plasticity and differentiation.
