title: Effect of chemoreceptor stimulation and inhibition on total pulmonary resistance in humans during NREM sleep.
abstract: We investigated the effect of chemoreceptor stimulation and inhibition on total pulmonary resistance (RL) during non-rapid-eye-movement (NREM) sleep in healthy subjects. Chemoreceptor stimulation was accomplished with brief isocapnic hypoxia (n = 8). Minute ventilation increased to 150% of room air control. RL at peak inspiratory flow decreased to 66% of room air control. Resistive pressure-inspiratory flow plots demonstrated lower resistive pressures for a given inspiratory flow. Chemoreceptor inhibition was accomplished by abruptly terminating brief hypocapnic hypoxia with 100% O2 (n = 7). Minute ventilation decreased to 63% of room air control. RL calculated at peak inspiratory or fixed flow did not change significantly, and pressure-flow plots at nadir ventilation showed no systematic change from room air control. We conclude that 1) hypoxic chemoreceptor stimulation is associated with decreased RL and enhancement of pressure-flow relationships, suggesting increased upper airway caliber; 2) upper airway patency is not compromised during periods of low ventilatory drive in normal subjects; and 3) upper airway dilating muscles and thoracic pump muscles are optionally coordinated with increased and decreased ventilatory drive.
authors.affiliation: Medical Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin.
authors.forename: M S
authors.initials: MS
authors.lastname: Badr
authors.forename: J B
authors.initials: JB
authors.lastname: Skatrud
authors.forename: J A
authors.initials: JA
authors.lastname: Dempsey
mesh_terms: D000328:Adult; D000403:Airway Resistance / Q000187:drug effects*; D001980:Bronchi / Q000503:physiopathology; D002245:Carbon Dioxide / Q000097:blood; D002628:Chemoreceptor Cells / Q000187:drug effects / Q000502:physiology*; D004569:Electroencephalography; D004576:Electromyography; D006801:Humans; D016857:Hypocapnia / Q000503:physiopathology; D000860:Hypoxia / Q000503:physiopathology; D017286:Polysomnography; D012129:Respiratory Function Tests; D015656:Respiratory Mechanics / Q000502:physiology; D012132:Respiratory Muscles / Q000502:physiology; D012890:Sleep / Q000502:physiology*; D012913:Snoring / Q000503:physiopathology
chemical_list: D002245:Carbon Dioxide