Related Experiment Video

Updated: Oct 7, 2026

Chemiluminescence-based Assays for Detection of Nitric Oxide and its Derivatives from Autoxidation and Nitrosated Compounds
08:23

Chemiluminescence-based Assays for Detection of Nitric Oxide and its Derivatives from Autoxidation and Nitrosated Compounds

Published on: February 16, 2022

Nitric Oxide Metabolites in Sickle Cell Anemia Patients after Oral Administration of Hydroxyurea; Hemoglobinopathy

Masoud Nahavandi1, Melville Q. Wyche, Elliott Perlin

  • 1Departments of Anesthesiology, Internal Medicine, and Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, DC.

Hematology (Amsterdam, Netherlands)
|June 16, 2001
PubMed

The mechanism of action of hydroxyurea (HU) in decreasing the frequency of pain crisis in sickle cell disease (SCD) has not been fully elucidated. In vitro and in vivo studies suggest that nitric oxide (NO), a potent vasodilator, may partly be responsible for the beneficial effect of HU. This study was designed to determine the effect of oral administration of HU on plasma levels of NO metabolites (NO(x) ) in sickle cell patients (SCP). The results indicate that during steady-state plasma levels of NO(x) were significantly higher in HU-treated patients compared to non HU-treated patients or normal controls (p <.05). In five inpatients in mild pain plasma levels of NO(x) increased significantly after 2 h of HU administration (p <.05); however, in three inpatients in persistent pain with significantly lower baseline NO(x) there was a minimal NO(x) response to HU at 2 h (p <.01). These observations indicate that HU administration is associated with the production of NO in some SCP, but that further study of the pharmacodynamics of this effect is necessary.

More Related Videos

Characterization of Sickling During Controlled Automated Deoxygenation with Oxygen Gradient Ektacytometry08:23

Characterization of Sickling During Controlled Automated Deoxygenation with Oxygen Gradient Ektacytometry

Published on: November 5, 2019

Immunostaining-Based Detection of Dynamic Alterations in Red Blood Cell Proteins10:07

Immunostaining-Based Detection of Dynamic Alterations in Red Blood Cell Proteins

Published on: March 17, 2023

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...
Antihypertensive Drugs: Vasodilators01:23

Antihypertensive Drugs: Vasodilators

Vasodilators, primarily affecting the smooth muscles within arterial and venous walls, are commonly used for hypertension treatment. Medications such as minoxidil and hydralazine primarily target arteries and arterioles, while sodium nitroprusside acts on arterioles and venules. Minoxidil, functioning as a prodrug, is metabolized by hepatic sulfotransferase into its active form, minoxidil sulfate, after oral administration. This metabolite binds to the sulfonylurea receptor (SUR) component of...
Treatment for Pulmonary Arterial Hypertension: Phosphodiesterase Inhibitors01:28

Treatment for Pulmonary Arterial Hypertension: Phosphodiesterase Inhibitors

Phosphodiesterase 5 (PDE5) inhibitors are potent enzymes that function to hydrolyze cyclic nucleotides to their corresponding 5' monophosphates. Their unique biochemical properties have been applied in treating Pulmonary Arterial Hypertension (PAH).
Among the PDE5 inhibitors, sildenafil (Revatio) stands out as a competitive and selective inhibitor. It operates by elevating cellular levels of cGMP and augmenting signaling through the cGMP-PKG pathway, promoting vasodilation. Upon oral...
Antianginal Drugs: Nitrates and &#946;-Blockers01:16

Antianginal Drugs: Nitrates and β-Blockers

In cardiovascular health, antianginal drugs combat angina pectoris — a condition marked by chest pain owing to diminished blood flow to the heart.
Organic nitrates,  such as nitroglycerin, play a pivotal role. Once metabolized, they liberate nitric oxide, a molecular marvel. Nitric oxide triggers guanylyl cyclase and augments cGMP production. This biochemical cascade orchestrates the relaxation of vascular smooth muscles, ushering in vasodilation and enhancing coronary blood flow. Administered...
Hypoxia01:23

Hypoxia

Hypoxia is a medical condition characterized by an inadequate oxygen supply to body tissues. It typically manifests as a bluish discoloration of the skin and mucosae, especially in fair-skinned individuals, when hemoglobin (Hb) saturation drops below 75%.
Types of Hypoxia
There are four primary types of hypoxia, each resulting from a different cause:
1. Anemic hypoxia: This type occurs due to insufficient oxygen delivery caused by a lack of red blood cells (RBCs) or RBCs with abnormal or...
Oxygen Transport in the Blood01:27

Oxygen Transport in the Blood

Hemoglobin (Hb) is a crucial molecule in the human body, consisting of four polypeptide chains, each bound to an iron-containing heme group. This unique structure enables hemoglobin to bind to oxygen, with each molecule capable of combining with four molecules of oxygen, leading to rapid and reversible oxygen loading. When fully loaded with oxygen, it is called oxyhemoglobin, while hemoglobin that has released oxygen is called reduced hemoglobin or deoxyhemoglobin. As hemoglobin binds oxygen,...