RT info:eu-repo/semantics/article
T1 Effects of cellular interactions on calcium dynamics in prolactin-secreting cells
A1 Abraham, Elizabeth J.
A1 Villalobos Jorge, Carlos
A1 Frawley, L. Stephen
K1 Cellular Interaction
K1 Interacción celular
K1 Calcium
K1 Calcio
K1 Prolactin
K1 Prolactina
AB Signals derived from other pituitary cells can have a dramatic effect on PRL gene expression and secretion by mammotropes. However, the intracellular mechanisms by which these effects are manifested on the target cell remain unexplored. Inasmuch as calcium is a key modulator of both gene expression and hormone export in mammotropes, we evaluated the effects of cell to cell contact vs. specific cellular interactions on calcium dynamics within these cells. This was accomplished by digital-imaging fluorescence microscopy of fura-2 in pituitary cells that were isolated in culture (singles) or adjoining one other cell (doublets). After calcium imaging, we then subjected cells to immunocytochemistry for PRL. Doublets were further categorized into mammotropes attached to another mammotrope (M-M) or to a nonmammotrope (M-nonM). We then calculated and compared Mean[ Ca2+]i values as well as Oscillation Indices (which reflect the oscillatory behavior of cells) in singles and doublets and found that they were not different (P> 0.05). However, the phenotype of the adjoining cell had a profound influence on both of these calcium parameters, such that the presence of one mammotrope could consistently decrease (P < 0.05) the Mean [Ca2+]i value (39.17 ± 3.83 vs. 56.24 ± 5.56 in M-nonM) and Oscillation Index (10.19 ± 1.76 vs. 21.21 ± 3.73 in M-nonM) of its neighboring counterpart. A more detailed analysis of oscillatory patterns in these cells revealed that nonoscillators were more abundant in M-M (23%) than in M-nonM (12%) doublets. Taken together, our results indicate that PRL-secreting cells convey a signal that dampens the oscillatory behavior of neighboring mammotropes. Thus, it appears that it is the phenotype rather than the physical presence of a neighbor that controls intercellular regulation of calcium dynamics among mammotropes.
PB Oxford University Press
SN 1945-7170
YR 1998
FD 1998
LK http://uvadoc.uva.es/handle/10324/45080
UL http://uvadoc.uva.es/handle/10324/45080
LA eng
NO Endocrinology, 1998, vol. 139, n. 6. p. 2988-2993
NO Producción Científica
DS UVaDOC
RD 26-dic-2024