Effects of corticotropin-releasing hormone on respiratory parameters during sleep in normal men

Summary

Corticotropin-releasing hormone (CRH) is well-known to be a centrally acting respiratory stimulant after systemic application both in healthy subjects and in patients suffering from respiratory failure. In order to study the effects of CRH on sleep EEG and respiratory parameters during sleep, 14 healthy male volunteers were investigated in a single-blind placebo controlled design. After an adaptation night, polysomnography was performed during two successive nights between 23.00 hrs. and 7.00 hrs. During one night placebo was applied, on the other 50 µg ovine CRH was administered intravenously as a bolus every hour from 0.00 hrs. to 6.00 hrs. For the assessment of respiration, blood oxygen saturation and thoracic wall movements were measured, as well as nasal and oral airflow using the thermistor method. Sleep efficiency parameters and subjective perception of sleep quality were not affected following CRH. The following alterations were found regarding sleep architecture: REM sleep as well as slow wave sleep showed a tendency to decrease under CRH, whereas light sleep tended to increase. After an injection of CRH a stimulation of respiration could be observed, with an increase of tidal volume over a time interval of a few minutes. Blood oxygen saturation was only slightly increased. Cortisol and ACTH concentrations were found to be constantly elevated. These results indicate that respiration during sleep is clearly affected by CRH with only slight alterations of global sleep parameters. No association was found between stimulation of ventilation and the occurrence of arousals; the respiratory analeptic effect of CRH thus appears to be specific. In conclusion, this may provide a basis for new pharmacological approaches to treat sleep-related breathing disorders.

Key words

CRH - respiration - sleep