Nitric oxide effects on human erythrocytes structural and functional properties--an in vitro study

Rui Mesquita1, Bruno Piçarra, Carlota Saldanha

  • 1Institute of Biochemistry. Faculty of Medicine of Lisbon, Portugal. ruimesquita@medscape.com

NO is present in the blood at 10(-7) M under physiological conditions, but at concentrations higher than 10(-6) M during inflammatory disease states. The aim of this study was to characterize what are the effects of these different NO concentrations on erythrocyte structural and functional properties. Blood was collected from eleven healthy men and incubated with SpermineNONOate in order to expose it during incubation time to NO concentrations between 10(-7) M and 10(-3) M. We measured erythrocyte aggregation and deformability, membrane lipid peroxidation and fluidity, p50, hemoglobin, oxyhemoglobin, methemoglobin concentrations and plasma pH, pO(2), pCO(2), Na(+), K(+) and Ca(2+). When blood was exposed to NO 10(-7) M erythrocyte deformability increase and p50 decrease. In presence of NO 10(-5) M lipid fluidity and p50 decrease. When blood was exposed to NO 10(-3) M methemoglobin concentration increase and erythrocyte deformability and p50 decrease but membrane fluidity and lipid peroxidation were similar to control. In conclusion, dependent of NO concentrations there is different effects on erythrocytes structural and functional properties.

Related Concept Videos

Nitric Oxide Signaling Pathway01:28

Nitric Oxide Signaling Pathway

Nitric oxide (NO), an inorganic gas, acts as a potent second messenger in most animal and plant tissues. NO diffuses out of the cells that produce it and enters the neighboring cells to generate a downstream response. NO synthase (NOS) catalyzes NO production by the deamination of the amino acid arginine. There are three isoforms of NOS. Endothelial cells have endothelial NOS (eNOS), nerve and muscle cells have neuronal NOS (nNOS), and macrophages produce inducible NOS (iNOS) upon exposure to...
Factors Affecting Erythropoiesis01:24

Factors Affecting Erythropoiesis

The cardiovascular system regulates the number of erythrocytes in the bloodstream to ensure optimal oxygen transport. It also prevents over-proliferation of these cells, which helps to maintain blood viscosity and flow rate.
Several factors influence the erythrocyte production rate, with tissue oxygen level being among the most critical. Intense exercise or high altitudes can cause tissue hypoxia, which triggers the kidneys to release more erythropoietin (EPO) into the bloodstream.
EPO then...
Structure and Function of Erythrocytes01:29

Structure and Function of Erythrocytes

There are between 4.2 and 6 million erythrocytes, also known as red blood cells, in every microliter of blood. These cells are small, flattened biconcave discs with centers that are depressed.
The erythrocyte plasma membrane is associated with proteins such as spectrin, which forms a flexible cytoplasmic meshwork. This meshwork allows erythrocytes to twist, turn, become cup-shaped, and regain their biconcave shape as they pass through narrow capillaries. Additionally, erythrocytes can form...