Uric acid inhibits liver phosphorylase a activity under simulated in vivo conditions

American Journal of Physiology. Endocrinology and Metabolism
Nacide Ercan-FangM C Gannon

Abstract

We have reported that glycogen synthesis and degradation can occur in vivo without a significant change in the amount of phosphorylase a present. These data suggest the presence of a regulatable mechanism for inhibiting phosphorylase a activity in vivo. Several effectors have been described. AMP stimulates, whereas ADP, ATP, and glucose inhibit activity. Of these effectors, only the glucose concentration changes under normal conditions; thus it could regulate phosphorylase a activity in vivo. We previously have reported that, when all of these effectors were present at physiological concentrations, the net effect was no change in phosphorylase a activity. Addition of caffeine, an independent inhibitor of activity, to the above effectors not only resulted in inhibition but also restored a glucose concentration-dependent inhibition. Because uric acid is an endogenous xanthine derivative, we decided to determine whether it had an effect on phosphorylase a activity. Independently, uric acid did not affect activity; however, when added at a presumed physiological concentration in combination with AMP, ADP, ATP, and glucose, it inhibited activity. A modest but not statistically significant glucose concentration-dependent inhibition w...Continue Reading

References

Aug 12, 1976·Biochimica Et Biophysica Acta·A W Tan, F Q Nuttall
Jul 21, 1992·Biochimica Et Biophysica Acta·A Di StefanoE Marinello
Apr 1, 1990·Proceedings of the National Academy of Sciences of the United States of America·A P KoretskyT Van Dyke
Nov 15, 1974·European Journal of Biochemistry·W StalmansH G Hers
Jan 1, 1984·The American Journal of Physiology·C B NiewoehnerF Q Nuttall
Oct 1, 1984·The American Journal of Physiology·C B NiewoehnerF Q Nuttall
Aug 1, 1995·The American Journal of Physiology·N ErcanF Q Nuttall
Apr 15, 1996·Archives of Biochemistry and Biophysics·N ErcanF Q Nuttall

Citations

Mar 31, 2005·American Journal of Physiology. Endocrinology and Metabolism·Nacide Ercan-FangF Q Nuttall
Jun 18, 2002·American Journal of Physiology. Endocrinology and Metabolism·Nacide Ercan-FangF Q Nuttall

Related Concepts

Adenine Nucleotides
Metazoa
Quick-Pep
Drug Combinations
Enzyme Inhibitors
Anhydrous Dextrose
Liver
Osmolality
Phosphorylase a
Urate

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Synthetic Genetic Array Analysis

Synthetic genetic arrays allow the systematic examination of genetic interactions. Here is the latest research focusing on synthetic genetic arrays and their analyses.

Congenital Hyperinsulinism

Congenital hyperinsulinism is caused by genetic mutations resulting in excess insulin secretion from beta cells of the pancreas. Here is the latest research.

Neural Activity: Imaging

Imaging of neural activity in vivo has developed rapidly recently with the advancement of fluorescence microscopy, including new applications using miniaturized microscopes (miniscopes). This feed follows the progress in this growing field.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Epigenetic Memory

Epigenetic memory refers to the heritable genetic changes that are not explained by the DNA sequence. Find the latest research on epigenetic memory here.

Cell Atlas of the Human Eye

Constructing a cell atlas of the human eye will require transcriptomic and histologic analysis over the lifespan. This understanding will aid in the study of development and disease. Find the latest research pertaining to the Cell Atlas of the Human Eye here.

Femoral Neoplasms

Femoral Neoplasms are bone tumors that arise in the femur. Discover the latest research on femoral neoplasms here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.