Interleukin-6 response to exercise and high-altitude exposure: influence of alpha -adrenergic blockade

• Published in: Journal of applied physiology (1985) Vol. 91; no. 5; pp. 2143 - 2149
• Main Authors: Mazzeo, Robert S, Donovan, Danielle, Fleshner, Monika, Butterfield, Gail E, Zamudio, Stacy, Wolfel, Eugene E, Moore, Lorna G
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Am Physiological Soc 01.11.2001; American Physiological Society
• Subjects: Adrenergic alpha-Agonists - pharmacology; Adrenergic alpha-Antagonists - pharmacology; Adult; Altitude; Anaerobic Threshold - physiology; Biological and medical sciences; Catecholamines - urine; Cytokines; Exercise; Exercise - physiology; Female; Fundamental and applied biological sciences. Psychology; Humans; Interleukin-6 - biosynthesis; Male; Menstrual Cycle - physiology; Neurotransmitters; Ovary - metabolism; Oxygen; Oxygen Consumption - physiology; Phenylephrine - pharmacology; Vertebrates: body movement. Posture. Locomotion. Flight. Swimming. Physical exercise. Rest. Sports; Physical exercise; Human; Interleukin 6; High altitude; Oxygen; α-Adrenergic receptor; Cytokine; Environmental factor; Hypoxia; Catecholamine; Stress
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/jappl.2001.91.5.2143

1  Department of Kinesiology and Applied Physiology, University of Colorado, Boulder, Colorado 80309; 2  Palo Alto Veterans Affairs Health Care System, Palo Alto, California 94304; and 3  University of Colorado Health Sciences Center, Denver, Colorado 80262 Interleukin-6 (IL-6), an important cytokine involved in a number of biological processes, is consistently elevated during periods of stress. The mechanisms responsible for the induction of IL-6 under these conditions remain uncertain. This study examined the effect of -adrenergic blockade on the IL-6 response to acute and chronic high-altitude exposure in women both at rest and during exercise. Sixteen healthy, eumenorrheic women (aged 23.2 ± 1.4   yr) participated in the study. Subjects received either -adrenergic blockade (prazosin, 3 mg/day) or a placebo in a double-blinded, randomized fashion. Subjects participated in submaximal exercise tests at sea level and on days 1  and 12  at altitude (4,300 m). Resting plasma and 24-h urine samples were collected throughout the duration of the study. At sea level, no differences were found at rest for plasma IL-6 between groups (1.5 ± 0.2 and 1.2 ± 0.3   pg/ml for placebo and blocked groups, respectively). On acute ascent to altitude, IL-6 levels increased significantly in both groups compared with sea-level values (57 and 84% for placebo and blocked groups, respectively). After 12 days of acclimatization, IL-6 levels remained elevated for placebo subjects; however, they returned to sea-level values in the blocked group. -Adrenergic blockade significantly lowered the IL-6 response to exercise both at sea level (46%) and at altitude (42%) compared with placebo. A significant correlation ( P  = 0.004) between resting IL-6 and urinary norepinephrine excretion rates was found over the course of time while at altitude. In conclusion, the results indicate a role for -adrenergic regulation of the IL-6 response to the stress of both short-term moderate-intensity exercise and hypoxia. hypoxia; catecholamines; norepinephrine; epinephrine; cytokines