Superior Efficacy of Pulsatile Versus Continuous Administration of Ovine Corticotropin Releasing Hormone in Healthy Man

Summary

The effect of continuous (50 µg and 100 µg/4 hrs) versus pulsatile (6.25 µg every 30 minutes equivalent to a total dose of 50 µg during 4 hours) administration of ovine corticotropin releasing factor (oCRF) was investigated in 6 healthy, male subjects. A rise in the plasma concentrations of ACTH and of cortisol was observed during the intermittent, but not during the continuous infusion of 50 µg oCRF/4 hours. Comparing the rise in the plasma concentrations of ACTH and cortisol above individual basal concentrations no differences were found between the continuous infusion of 100 µg oCRF and the pulsatile administration of 50 µg oCRF. Response to pulsatile (50 µg/4 hrs) and continuous (100 µg/4 hrs) administration of oCRF, but lack of response to continuous infusion at a rate of 50 µg/4 hrs was also reflected by the calculated mean sum of increments of cortisol above individual basal concentrations. These results indicate a superior efficacy of intermittent versus continuous administration of oCRF in healthy man.

Key words

CRF - Pulsatile administration - Continuous infusion - Healthy men - Plasma ACTH - Cortisol