Work

The biological lifetime of nitric oxide: Implications for the perivascular dynamics of NO and O 2

Year: 2000

Type: article

Abstract: Endothelial nitric oxide (nitrogen monoxide) is synthesized at the intravascular/extravascular interface. We previously have reported the intravascular half-life of NO, as a result of consumption by erythrocytes, as approximately 2 ms. We report here studies designed to estimate the lifetime of NO in the parenchymal (extravascular) tissue and describe the implications of these results for the distribution of NO and oxygen concentration gradients away from the blood vessel. The rate of consumption of NO by parenchymal cells (hepatocytes) linearly depends on both NO and O(2) concentration. We estimate that the extravascular half-life of NO will range from 0.09 to > 2 s, depending on O2 concentration and thus distance from the vessel. Computer modeling reveals that this phenomenon, coupled with reversible NO inhibition of cellular mitochondrial oxygen consumption, substantially extends the zone of adequate tissue cellular oxygenation away from the blood vessel, with an especially dramatic effect during conditions of increased tissue work (oxygen consumption). This represents a second action of NO, in addition to vasodilation, in enhancing tissue cellular respiration and provides a possible physiological function for the known reversible inhibition of mitochondrial respiration by low concentrations of NO.

Source: Proceedings of the National Academy of Sciences

DOI: 10.1073/pnas.98.1.355

Authors: Douglas D. Thomas, Xiaoping Liu, Stephen P. Kantrow, Jack R. Lancaster

Institutions: Johns Hopkins University, Johns Hopkins Medicine, Louisiana State University Health Sciences Center New Orleans

Language: English

Topic: Nitric Oxide and Endothelin Effects

Subfield: Physiology

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: green

Funder: National Institute of Diabetes and Digestive and Kidney Diseases