title: Secretion of adrenocorticotropin, beta-endorphin and calcitonin by cultured medullary thyroid carcinoma cells. Effects of synthetic corticotropin-releasing factor and lysine vasopressin.
abstract: The present study was performed to investigate the potential of human medullary thyroid carcinoma (MTC) cells to secrete ACTH, beta-LPH/beta-EP. In addition, these studies might shed further light on the possible synthesis of a common precursor molecule for calcitonin (CT), ACTH and beta-LPH/beta-EP. MTC tissue was obtained from 10 patients (6 familial, 4 sporadic) without clinical and biochemical signs of Cushing's syndrome. Single cell suspensions were cultured for 1 to 2 weeks. Mean basal release of beta-LPH/beta-EP was 0.76 +/- 0.29 (SE) ng/10(6) cells/4 h (n = 10). Dibutyryl cyclic AMP (3 mM) stimulated beta-EP release significantly in 3 out of 7 cultures, while Ca2+ (2 mM) had no effect at all. The effects of the physiological regulators of pituitary ACTH and beta-LPH/beta-EP secretion, synthetic corticotropin-releasing factor (CRF-41) and vasopressin (LVP) were also studied in these MTC cell cultures. LVP (100 nM) had no effect on beta-EP release from MTC cells of all 8 cultures investigated. CRF-41 (10 nM) stimulated beta-EP release from 5 cultures and was without effect on 4. Maximal stimulation was noticed with 10 nM, while the effect of 100 nM CRF-41 was lower or absent. Stimulation was most outspoken in 3 cultures of familial MTC, whereas in 2 cultures of sporadic MTC CRF-41 stimulated beta-EP release marginally only after a 24 h incubation. LVP and/or CRF-41 stimulated CT release significantly in 3 cultures from sporadic MTC, while in these cultures the effect of CRF-41 on beta-EP release was either very small or absent.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000378:metabolism*; D003994:Bucladesine / Q000494:pharmacology; D002116:Calcitonin / Q000378:metabolism*; D002118:Calcium / Q000494:pharmacology; D002277:Carcinoma / Q000378:metabolism*; D002478:Cells, Cultured; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology*; D004723:Endorphins / Q000378:metabolism*; D005260:Female; D006801:Humans; D008236:Lypressin / Q000494:pharmacology*; D008297:Male; D013964:Thyroid Neoplasms / Q000378:metabolism*; D001615:beta-Endorphin
chemical_list: D004723:Endorphins; D008236:Lypressin; D001615:beta-Endorphin; D003994:Bucladesine; D000324:Adrenocorticotropic Hormone; D002116:Calcitonin; D003346:Corticotropin-Releasing Hormone; D002118:Calcium