Blood sampling procedures influence serum calcitonin concentrations in rats

The aim of this study was to determine whether serum calcitonin (S-CT) in rats is influenced by the method of taking blood samples. Sampling during halothane anaesthesia, after repeated administration of anaesthesia after a 14-day interval, and sampling without the use of anaesthetics (i.e. after the rats were made unconscious by stunning), resulted in different S-CT values (P≤0.001), whereas Ca 2+ levels were not affected. In thyroidectomized rats, the S-CT values after stunning were not significantly different whereas those in sham-operated rats were different (P≤0.01)