The respiratory responses to theophylline during normoxia and hypoxia were determined in 13 un-anesthetized fetal sheep. Theophylline (plasma levels ~ 111 μmol/L) increased the incidence of fetal breathing movements measured over 120 min from 37.7 ± 4.8% to 61.1 ± 5.7% (SEM) in normoxic fetuses. In isocapnic hypoxia (arterial O2 tension ~1.86 kPa), theophylline increased the incidence from 20.0 ± 6.3 to 52.0 ± 6.1%. Theophylline also resulted in an increase in the slope of inspiration during both normoxia and hypoxia. We conclude that adenosine modulates fetal respiratory drive during normoxia and hypoxia.
|Original language||English (US)|
|Number of pages||4|
|Publication status||Published - 1990|
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health