Stimulating effect of calcium channel activator BAY-K 8644 on calcitonin secretion.
The calcium channel activator BAY-K 8644 injected intravenously produces a significant rise in the calcitonin content of the thyroid. Because adrenalin and noradrenaline play a certain role in the regulation of ionic calcium channels and in the preservation of the secretory tonus of the calcitonin secreting C cells, the effect of BAY-K 8644 was followed-up in adrenalectomized animals and in animals in which propranolol was previously administered. Adrenalectomy of beta receptor blocking does not prevent the effect of BAY-K 8644 on the activation of calcium channels, the calcitonin secretion being stimulated in these conditions too. The data obtained stress the relative independence of the calcium channels or the beta-adrenergic stimulating system in the achievement of calcium ion transfer. However, the calcitonin levels obtained were lower in adrenalectomized animals or following propranolol after stimulation with BAY-K 8644 in those with intact sympatho-adrenergic tonus. This stresses the importance of the integrity of the beta receptors in the activation of the calcium channels.
Gozariu
L
L
Department of Endocrinology, Institute of Medicine and Pharmacy, Cluj-Napoca, Romania.
Orbai
P
P
Barabaş
E
E
Strîmbu
M G
MG
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology*; D000315:Adrenalectomy; D000818:Animals; D002116:Calcitonin / Q000032:analysis / Q000187:drug effects* / Q000378:metabolism; D015220:Calcium Channels / Q000187:drug effects* / Q000378:metabolism; D004347:Drug Interactions; D008297:Male; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D013268:Stimulation, Chemical; D013961:Thyroid Gland / Q000032:analysis / Q000187:drug effects / Q000378:metabolism
D015220:Calcium Channels; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D002116:Calcitonin; D011433:Propranolol