Potential Biomarker Peptides Associated with Acute Alcohol-Induced Reduction of Blood Pressure

Abstract

The purpose of this study was to explore the peptides that are related to acute reduction of blood pressure after alcohol drinking. Venous blood was collected from male healthy volunteers before and after drinking white wine (3 ml/kg weight) containing 13% of ethanol. Peptidome analysis for serum samples was performed using a new target plate, BLOTCHIP®. Alcohol caused significant decreases in systolic and diastolic blood pressure levels at 45 min. The peptidome analysis showed that the levels of three peptides of m/z 1467, 2380 and 2662 changed significantly after drinking. The m/z 1467 and 2662 peptides were identified to be fragments of fibrinogen alpha chain, and the m/z 2380 peptide was identified to be a fragment of complement C4. The intensities of the m/z 2380 and m/z 1467 peptides before drinking were associated with % decreases in systolic and diastolic blood pressure levels at 45 min after drinking compared with the levels before drinking, while there were no significant correlations between the intensity of the m/z 2662 peptide and % decreases in systolic and diastolic blood pressure levels after drinking. The m/z 1467 and 2380 peptides are suggested to be markers for acute reduction of blood pressure after drinking alcohol.

Fig 1. Changes in systolic (A) and diastolic (B) blood pressure levels after drinking alcohol.

Blood pressure was measured just before dinking and at 45 min and 2–3 hr after drinking. Means ± standard errors of blood pressure levels are shown. Asterisks denote significant differences from the levels before drinking (**, p < 0.01).

Fig 2. Differential profiling of serum sampled from subjects before and after drinking.

Each integrated spectrum normalized with ClinPro Tools version 2.2 is the average of 10 samples (total of 44 integrations) from subjects.

Fig 3. MS/MS structural analysis of m/z 1467 (A), 2380 (B), 2662 (C) peptides in the sample after reversed-phase high-pressure liquid chromatography separation.

Fig 4. Changes in intensities of m/z 1467 (A), 2380 (B) and 2662 (C) peptides after drinking alcohol.

Medians with 25 and 75 percentile values of intensities of the peptides are shown using box plots. Intensities of each peptide in serum collected just before dinking and at 45 min and 2–3 hr after drinking were measured by mass spectrometry using BLOTCHIP^®. Symbols denote significant differences from the levels before drinking (*, p < 0.05; **, p < 0.01) and the levels at 45 min after drinking (†, p < 0.05; ††, p < 0.01). #, a marginally significant difference from the intensity before drinking (p = 0.074).

Fig 5. Scatter plots of the relationships between ranks of serum m/z 2380 peptide intensity before drinking and % changes in systolic (A) and diastolic (B) blood pressure at 45 min after drinking.

Spearman’s rank correlation coefficients (r) are given in the figures.

Fig 6. A. Changes in blood complement C4a level after drinking alcohol. Complement C4a concentration was measured just before drinking and at 45 min and 2–3 hr after drinking. Means ± standard errors of complement C4a levels are shown. An asterisk denotes a significant difference from the level before drinking (*, p < 0.05). B,C. Scatter plots of the relationships between blood complement C4a level before drinking and % changes in systolic (B) and diastolic (C) blood pressure at 45 min after drinking.

Pearson’s correlation coefficients (r) are given in the figures.