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Chloroquine Decreases Adrenocorticotrophin‐Secretory Response to Corticotrophin‐Releasing Factor but not to Vasopressin in Rat Pituitary Cells: Further Evidence for Differentially Responsive Subpopulations
Author(s) -
Schwartz Jeffrey,
Pham Thao,
Funder John W.
Publication year - 1990
Publication title -
journal of neuroendocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.062
H-Index - 116
eISSN - 1365-2826
pISSN - 0953-8194
DOI - 10.1111/j.1365-2826.1990.tb00388.x
Subject(s) - medicine , endocrinology , vasopressin , basal (medicine) , secretion , acth secretion , adrenocorticotropic hormone , anterior pituitary , incubation , chemistry , peptide hormone , biology , hormone , biochemistry , insulin
The relationships between adrenocorticotrophin (ACTH) content, basal ACTH secretion and the ACTH‐secretory response to corticotrophin‐releasing factor (CRF) or vasopressin in cultured rat anterior pituitary cells were examined in studies using chloroquine, an agent that diverts nascent ACTH from a storage pathway to direct release from cells. Chloroquine (200 mUM from t=minus 2 h) significantly elevated the basal ACTH secretory rate (by 0.7 ± 0.2 ng over 30 min incubation, 1.1 ± 0.3 ng over 60 min and 2.3 ± 0.6 ng over 120 min). It also decreased the ACTH‐secretory response to CRF (2.9±0.5 vs 4.6 ± 0.5 ng/well over 30 min; 4.3 ± 0.7 vs 8.0 ± 1.4 ng/well over 60 min; 12.4±1.7 vs 20.2 ± 3.6 ng/well over 120 min). In marked contrast, the net responses to vasopressin were unaltered (0.9 ± 0.3 vs 0.9±0.2 ng/well over 30 min; 2.2 ± 0.9 vs 2.1 ±0.3 ng/well over 60 min; 3.8±0.9 vs 3.3 ± 1.0 ng/well over 120 min). These data further support the association of the ACTH‐secretory response to CRF with stored cellular ACTH, and the minimal dependence of the response to vasopressin on stored ACTH.