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Acute alcohol ingestion blunts arterial pressure but not sympathetic neural responses to orthostatic stress in humans
Author(s) -
Stream Sarah F,
Schwartz Christopher E,
Klein Jenna C,
Carter Jason R
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.1020.5
Subject(s) - orthostatic vital signs , blood pressure , medicine , placebo , heart rate , mean arterial pressure , anesthesia , alcohol , ingestion , cardiology , chemistry , pathology , biochemistry , alternative medicine
Acute alcohol consumption has been reported to decrease mean arterial pressure (MAP) during orthostatic challenge, a response that may contribute to alcohol‐mediated syncope. Muscle sympathetic nerve activity (MSNA) increases during orthostatic stress to help maintain MAP, yet the influence of alcohol on MSNA during orthostatic stress has not been determined. We hypothesize that alcohol ingestion will blunt MSNA responses to lower body negative pressure (LBNP). MAP, MSNA, and heart rate (HR) were recorded during progressive LBNP (−5, −10, −15, −20, −30, and −40 mmHg; 3 min/stage) in 22 subjects (age 25 ± 1 yrs). After a baseline progressive LBNP (Trial 1), subjects were randomly assigned to either the placebo (n=11) or alcohol (n=11) group and repeated the progressive LBNP (Trial 2). Resting MAP increased (P<0.05) similarly with placebo (83 ± 2 to 88 ± 2 mmHg) and alcohol (82 ± 2 to 87 ± 3 mmHg). Resting HR (60 ± 2 to 64 ± 2 beats/min) and MSNA (15 ± 4 to 24 ± 4 bursts/min) increased (P<0.05) with alcohol, but not placebo. A significant time × condition × group interaction (P<0.05) was observed for MAP, demonstrating a more pronounced decrease in MAP during progressive LBNP with alcohol. MSNA and HR increased during all LBNP protocols, but there were no differences between trials or groups. In conclusion, alcohol decreases MAP responses to orthostatic stress, but these decreases do not appear to be mediated by MSNA. Supported by NIH.