TY - JOUR
T1 - Evidence that AVP receptors in AtT-20 corticotrophs are not coupled to secretion of POMC-derived peptides
AU - Lutz-Bucher, Bernadette
AU - Jeandel, Lydie
AU - Heisler, Seymour
AU - Roberts, James L.
AU - Koch, Bernard
N1 - Funding Information:
This study was supported by grants from the Medical Research Council of Canada (S.H.), the France-Canada Exchange Program (FRSQ-MRE; S.H.) and the INSERM (Contract Nr. 864009; B.L.-B. and B.K.). We are grateful to A. Eberle and the NIH for the generous gifts of antisera. We also thank Mrs. L. LePersonnic, F. Herzog and D. Desjardins for skilfuf technical assistance.
PY - 1987/10
Y1 - 1987/10
N2 - This study reports the presence in AtT-20 corticotrophs of high affinity-low capacity receptors for arginine-vasopressin (AVP), whose binding capacity was considerably enhanced by the divalent metal ion nickel. These binding sites, when analyzed in the presence of nickel, showed high affinity for AVP, vasotocin and oxytocin, but recognized to a lesser extent the V2-agonist 1-deamino-AVP, as well as V1-antagonists. Surprisingly, AVP failed to alter secretion of proopiomelanocortin (POMC)-derived peptides from the cells or corticotropin-releasing factor (CRF)-induced cAMP synthesis, as reported in normal corticotrophs. Exposure of cells to CRF elicited an increase in mRNAPOMC levels, while, in contrast, AVP was without significant effect. It thus appears that in AtT-20 tumor cells, the AVP receptors are not coupled to either the biochemical or biological cellular response.
AB - This study reports the presence in AtT-20 corticotrophs of high affinity-low capacity receptors for arginine-vasopressin (AVP), whose binding capacity was considerably enhanced by the divalent metal ion nickel. These binding sites, when analyzed in the presence of nickel, showed high affinity for AVP, vasotocin and oxytocin, but recognized to a lesser extent the V2-agonist 1-deamino-AVP, as well as V1-antagonists. Surprisingly, AVP failed to alter secretion of proopiomelanocortin (POMC)-derived peptides from the cells or corticotropin-releasing factor (CRF)-induced cAMP synthesis, as reported in normal corticotrophs. Exposure of cells to CRF elicited an increase in mRNAPOMC levels, while, in contrast, AVP was without significant effect. It thus appears that in AtT-20 tumor cells, the AVP receptors are not coupled to either the biochemical or biological cellular response.
KW - ACTH and α-MSH secretion
KW - Arginine-vasopressin receptor
KW - AtT-20 corticotroph
KW - mRNA
UR - http://www.scopus.com/inward/record.url?scp=0023227582&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0023227582&partnerID=8YFLogxK
U2 - 10.1016/0303-7207(87)90170-5
DO - 10.1016/0303-7207(87)90170-5
M3 - Article
C2 - 2822511
AN - SCOPUS:0023227582
SN - 0303-7207
VL - 53
SP - 161
EP - 167
JO - Molecular and Cellular Endocrinology
JF - Molecular and Cellular Endocrinology
IS - 3
ER -