Rapid pulsatile corticosterone secretion in the rat is not confirmed.

We attempted to confirm and extend a previous suggestion by other workers that, in the rat, corticosterone may be released as a series of very short pulses with a period of one minute. We measured the corticosterone concentration in the blood of chronically cannulated, unanaesthetised male rats, repeatedly, at ten second intervals, for periods of up to 25 minutes while the rats were engaged in normal activity or sleep or were subject to acute or chronic stress. We could find no evidence of the proposed rapid pulsatile secretion and suggest that the earlier finding may have been artifactual.