TY - JOUR
T1 - Role of the second-messenger cyclic-adenosine 5′-diphosphate-ribose on adrenocorticotropin secretion from pituitary cells
AU - Soares, Sandra M.
AU - Thompson, Michael
AU - Chini, Eduardo N.
PY - 2005/5
Y1 - 2005/5
N2 - We examined the role of the second-messenger cyclic-ADP-ribose (cADPR) on the regulation of ACTH secretion using AtT20 corticotroph tumor cell line. We found that the cADPR antagonist, 8-Br-cADPR, substantially diminished the secretion of ACTH induced by CRH and potassium in these cells, whereas xestospongin C, an inositol 1,4,5-triphosphata receptor antagonist, had no effect. In addition, the cADPR agonist, 3-deaza-cADPR, augmented ACTH secretion. The presence of the components of the cADPR system, namely ryanodine receptor, CD38, and cADPR itself, was determined in AtT20 cells. Furthermore, we observed that antagonists of the ryanodine channel and cADPR system can decrease the potassium-induced Ca2+ transients in these cells. These results suggest that cADPR is a second messenger in pituitary cells and regulates ACTH secretion by a mechanism dependent on activation of the ryanodine channel by extracellular Ca2+.
AB - We examined the role of the second-messenger cyclic-ADP-ribose (cADPR) on the regulation of ACTH secretion using AtT20 corticotroph tumor cell line. We found that the cADPR antagonist, 8-Br-cADPR, substantially diminished the secretion of ACTH induced by CRH and potassium in these cells, whereas xestospongin C, an inositol 1,4,5-triphosphata receptor antagonist, had no effect. In addition, the cADPR agonist, 3-deaza-cADPR, augmented ACTH secretion. The presence of the components of the cADPR system, namely ryanodine receptor, CD38, and cADPR itself, was determined in AtT20 cells. Furthermore, we observed that antagonists of the ryanodine channel and cADPR system can decrease the potassium-induced Ca2+ transients in these cells. These results suggest that cADPR is a second messenger in pituitary cells and regulates ACTH secretion by a mechanism dependent on activation of the ryanodine channel by extracellular Ca2+.
UR - http://www.scopus.com/inward/record.url?scp=17744394099&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=17744394099&partnerID=8YFLogxK
U2 - 10.1210/en.2004-1298
DO - 10.1210/en.2004-1298
M3 - Article
C2 - 15718277
AN - SCOPUS:17744394099
SN - 0013-7227
VL - 146
SP - 2186
EP - 2192
JO - Endocrinology
JF - Endocrinology
IS - 5
ER -