TY - JOUR
T1 - Cholecystokinin peptides as local modulators of thyroidal calcitonin secretion in the dog?
AU - Laurberg, P
AU - Rehfeld, J F
PY - 1987/10
Y1 - 1987/10
N2 - Cholecystokinin (CCK) is a heterogeneous gut hormone which is also synthetized in extra-intestinal endocrine cells and neurons. In order to examine the possibility that CCK peptides are local modulators of calcitonin secretion, we have studied the structure-activity relationship on calcitonin secretion from perfused canine thyroid lobes as well as the presence and molecular nature of CCK in the thyroid. Peptides containing the intact COOH-terminal tetrapeptide amide of CCK (CCK-4, CCK-5, pentagastrin, CCK-8 and gastrin-17) all induced dose-dependent (0.1, 3 and 100 nmol/l) increases in calcitonin release (P less than 0.05, n = 4) with biphasic secretion during 6-min infusion periods. The deamidated tetrapeptide and the COOH-terminal tripeptide were without effect. Gel chromatography of neutral water and acid-ethanol extracts of thyroid tissue, monitored by sequence-specific CCK and gastrin radioimmunoassays, disclosed a variety of CCK and gastrin peptides of which a predominant form resembled small molecular forms like CCK-4 and CCK-5. The presence in the thyroid of small CCK-like peptides and the pronounced effect of such peptides on calcitonin secretion suggest that calcitonin secretion is modulated by local release of small CCK peptides. They could originate from intrathyroidal nerves or from sub-populations of C-cells.
AB - Cholecystokinin (CCK) is a heterogeneous gut hormone which is also synthetized in extra-intestinal endocrine cells and neurons. In order to examine the possibility that CCK peptides are local modulators of calcitonin secretion, we have studied the structure-activity relationship on calcitonin secretion from perfused canine thyroid lobes as well as the presence and molecular nature of CCK in the thyroid. Peptides containing the intact COOH-terminal tetrapeptide amide of CCK (CCK-4, CCK-5, pentagastrin, CCK-8 and gastrin-17) all induced dose-dependent (0.1, 3 and 100 nmol/l) increases in calcitonin release (P less than 0.05, n = 4) with biphasic secretion during 6-min infusion periods. The deamidated tetrapeptide and the COOH-terminal tripeptide were without effect. Gel chromatography of neutral water and acid-ethanol extracts of thyroid tissue, monitored by sequence-specific CCK and gastrin radioimmunoassays, disclosed a variety of CCK and gastrin peptides of which a predominant form resembled small molecular forms like CCK-4 and CCK-5. The presence in the thyroid of small CCK-like peptides and the pronounced effect of such peptides on calcitonin secretion suggest that calcitonin secretion is modulated by local release of small CCK peptides. They could originate from intrathyroidal nerves or from sub-populations of C-cells.
KW - Animals
KW - Calcitonin/metabolism
KW - Cholecystokinin/pharmacology
KW - Dogs
KW - Gastrins/pharmacology
KW - Structure-Activity Relationship
KW - Thyroid Gland/drug effects
U2 - 10.1677/joe.0.1150077
DO - 10.1677/joe.0.1150077
M3 - Journal article
C2 - 3668449
SN - 0022-0795
VL - 115
SP - 77
EP - 82
JO - Journal of Endocrinology
JF - Journal of Endocrinology
IS - 1
ER -