Altered purine and glycogen metabolism in skeletal muscle during exercise in patients with heart failure

Metabonomics: A Useful Tool to Reveal Underlying Relationships between Altered Chinese Medicine Syndromes and Ultrafiltration in Treatment of Heart Failure

OBJECTIVE

To reveal the underlying relationships between Chinese medicine (CM) syndromes and ultrafiltration (UF) in the treatment of heart failure based on a metabonomic approach.

METHODS

Seventeen acute decompensated heart failure (ADHF) patients were enrolled, and their CM syndromes before and after UF were collected. In addition, their venous plasma collected before and after UF was used for liquid chromatographmass spectrometer-based metabonomic analysis. Both reversed phase liquid chromatography and hydrophilic interaction liquid chromatography were used to analyze the plasma samples. Partial least-squares to latent structure-discriminant analyses were used for data analysis.

RESULTS

An obvious difference was observed pre- and post-treatment. A total of 17 potential biomarkers associating with alterd syndromes with UF including hypoxanthine, 1-methylhistidine, phytosphingosine, O-decanoyl-R-carnitine, etc. were screened out, showing a significant change after UF. The major adjusted metabolic pathways were purine metabolism, histidine metabolism, leucine and isoleucine metabolism, arginine and proline metabolism, carnitine shuttle, sphingolipid metabolism and phospholipid metabolism.

CONCLUSIONS

Metabonomic approach is a useful tool to identify potential biomarkers of altered syndromes link to UF and could provide a theoretical basis for further research on the therapeutic mechanism of UF combined with CM.

The dysfunction of ammonia in heart failure increases with an increase in the intensity of resistance exercise, even with the use of appropriate drug therapy

BACKGROUND

Hyperammonemia during rest periods is a dysfunction in heart failure (HF). The low formation of ammonia during exercise reflects an inefficiency of purine metabolism. Hyperkalemia in response to physical exercise is common in HF and may contribute to a contractile inefficiency in type II fibers, leading to early fatigue. We tested the hypothesis that during resistance exercise of high intensity and low volume, this disorder of ammonia metabolism would be more intense, due to the hyperkalemia present in HF.

METHODS

Alternating resistance exercise (RE) of low intensity and high volume, and high intensity and low volume, were applied to 18 patients with an interval of 7 days between them (functional class II-III New York Heart Association, FE = 33.5 ± 4%) and compared with 22 healthy controls matched for age and gender. Ammonia, potassium and lactate levels were assessed before and immediately after the RE.

RESULTS

Significant differences: Deltas (control vs. HF) in 40% RE: lactate (mg/dl) 26.3 ± 10 vs. 37.7 ± 7; p < 0,001, ammonia (ug/dl) 92.5 ± 18 vs. 48.9 ± 9; p < 0.001. Deltas (control vs. HF) in 80%RE: lactate(mg/dl) 45.0 ± 12 vs. 54.1 ± 11; p < 0.05, ammonia(ug/dl) 133.5 ± 22 vs. 32.2 ± 7; p < 0.001, potassium (mEq/L) 1.6 ± 0.4 vs. 2.0 ± 0.8; p < 0.05. A negative correlation was found between the deltas of ammonia and potassium (r = -0.74, p < 0.001) in the HF group.

CONCLUSIONS

We conclude that in HF, there is an inefficiency of purine metabolism that increases with increasing exercise intensity, but not with an increase of total volume. These findings suggest that hyperkalemia may play an important role in the disorders of purine metabolism.

Catabolism of adenine nucleotides favors adenosine production following exercise in patients with chronic heart failure

BACKGROUND

Adenosine 5'-triphosphate is catabolized to adenosine 5'-monophosphate (AMP), which is further degraded by 2 pathways: deamination to inosine 5'-monophosphate and ammonia by AMP deaminase, or dephosphorylation to adenosine and inorganic phosphate by 5'-nucleotidase. Because adenosine is believed to be cardioprotective and we have reported that ammonia production decreased after exercise in patients with chronic heart failure (CHF), we determined if plasma adenosine levels after exercise increases in patients with CHF.

METHODS AND RESULTS

Maximal ergometer exercise tests with expired gas analysis were performed in 51 patients with CHF (age = 61 +/- 2 years, New York Heart Association [NYHA] class I/II/III = 19/18/14) and 20 age-matched normal controls. Serial changes in both plasma ammonia and adenosine levels were determined. The ratio for delta ammonia to peak work rate became smaller (control, NYHA I/II/III: 0.59 +/- 0.13/0.41 +/- 0.06/0.37 +/- 0.10/0.22 +/- 0.11 microg/dL x watts, respectively) and the ratio for delta adenosine to peak work rate was significantly higher in class III CHF (control, NYHA I/II/III: 0.93 +/- 0.21/0.86 +/- 0.14/1.11 +/- 0.27/2.92 +/- 0.67 nmol/L x watts, respectively).

CONCLUSION

In patients with CHF after exercise, the plasma levels of adenosine increased along with the decrease in the plasma levels of ammonia. Considering the physiologic cardioprotective actions of adenosine, the enhanced adenosine production after exercise may be an important adaptive response in patients with CHF.