Abstract
The aim of the study was to assess the involvement of the adenylate cyclase system in calcitonin (CT) secretion from thyroidal C-cells. The cAMP analogues Br-cAMP (10(-6) and 10(-4) mol/l) and DB-cAMP (10(-4) mol/l) and the activators of adenylate cyclase cholera toxin (0.1 microgram/ml and 5 micrograms/ml) and forskolin (10(-7) mol/l and 10(-5) mol/l) were infused for 6 min periods in perfused dog thyroid lobes. CT was measured in thyroid effluent by radioimmunoassay. Br-cAMP and cholera toxin did not alter basal CT secretion. DB-cAMP had a minimal stimulatory effect and forskolin 10(-5) mol/l a moderate stimulatory effect. This was much less than the effect of increasing perfusate Ca++ from 1.5 to 2.0 mmol/l. 10(-4) mol/l Br-cAMP increased the response to Ca++ with approximately 50 per cent. These results suggest that the activity of the adenylate cyclase system of the C-cells by itself is of little importance for CT secretion, but that it may have a role as modulator of the response to Ca++.
Original language | English |
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Journal | Hormone and Metabolic Research |
Volume | 20 |
Issue number | 5 |
Pages (from-to) | 261-3 |
Number of pages | 3 |
ISSN | 0018-5043 |
DOIs | |
Publication status | Published - 1988 |
Externally published | Yes |
Keywords
- 8-Bromo Cyclic Adenosine Monophosphate
- Adenylate Cyclase
- Animals
- Bucladesine
- Calcitonin
- Cholera Toxin
- Colforsin
- Dogs
- In Vitro Techniques
- Thyroid Gland