title: Autonomic nervous activity and stress hormones induced by hyperbaric saturation diving.
abstract: This study describes the changes in autonomic nervous activity and stress hormones during a hyperbaric saturation dive up to 4.1 MPa in six subjects. Their autonomic nervous activity was assessed by a power spectrum analysis of heart rate variability (HRV). The levels of plasma epinephrine (E) and norepinephrine (NE), and those of salivary chromogranin A and cortisol, were compared with the pre-dive control levels. Restrained activity of the cardiac vagal nerve was recognized in the early post-dive period by a decrease in high frequency power and by the standard deviation of the HRV. By contrast, enhanced activity of sympathetic nerve was recognized in the early post-dive period by an elevated plasma E, and also in the late 3.1 MPa, 4.1 MPa, and post-dive periods by elevated plasma NE. The levels of plasma E and NE were the most sensitive indicators of sympathetic nervous activity. A joint utilization of HRV parameters with stress hormones may be an effective means of estimating the adaptive responses between hyperbaric and normobaric environments.
authors.affiliation: Department of Hygiene and Space Medicine, Nihon University School of Medicine, Itabashi-ku, Tokyo 173-8610, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Hirayanagi
authors.forename: K
authors.initials: K
authors.lastname: Nakabayashi
authors.forename: K
authors.initials: K
authors.lastname: Okonogi
authors.forename: H
authors.initials: H
authors.lastname: Ohiwa
mesh_terms: D000328:Adult; D001341:Autonomic Nervous System / Q000502:physiology*; D015415:Biomarkers / Q000032:analysis; D001794:Blood Pressure; D053379:Chromogranin A; D002864:Chromogranins / Q000032:analysis; D004242:Diving / Q000502:physiology*; D004837:Epinephrine / Q000097:blood; D006321:Heart / Q000294:innervation; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis; D008297:Male; D009638:Norepinephrine / Q000097:blood; D012463:Saliva / Q000737:chemistry
chemical_list: D015415:Biomarkers; D053379:Chromogranin A; D002864:Chromogranins; D006854:Hydrocortisone; D009638:Norepinephrine; D004837:Epinephrine