New product: Highly Sensitive Citrulline ELISA kit validated for plasma samples

Just released, our Citrulline ELISA kit completes our range of ELISA kits designed to assess arginine metabolism and nitric oxide production. Highly sensitive and requiring only a minimal sample volume of 20 µL, the kit has been validated for the quantification of Citrulline in plasma samples.

Citrulline is a non-essential amino acid primarily produced in the small intestine by enterocytes, from glutamine and proline. Upon release in the bloodstream, citrulline is transported to the kidneys, where it can be converted into arginine to maintain arginine homeostasis. Citrulline is also synthesized in the liver from ornithine and carbamoyl phosphate, where it participates in the urea cycle (conversion of ammonia into urea for excretion). Finally, citrulline is synthesized by endothelial cells, neurons, and immune cells during the conversion of arginine into nitric oxide, a process that regulates vascular tone, blood flow, neurotransmission, and modulates inflammation.

Baseline levels of Citrulline in human plasma range from 20 to 40 μmol/L. With a limit of detection of 1.47 μmol, cross-validated by LC-MS, our Citrulline ELISA kit constitutes an easy and accurate solution to assess citrulline levels in a wide array of contexts:

• Diagnosis of Urea Cycle Disorders: Elevated or reduced plasma levels of Citrulline can pinpoint specific enzyme deficiencies within the urea cycle. In certain pathological conditions, elevated citrulline levels are associated with ammonia accumulation, which can alter brain function (confusion, seizures).
• Biomarker of Gut Integrity: Low plasma levels of citrulline may indicate intestinal failure or damage. In patients with intestinal resections, citrulline can be used to monitor recovery of enterocyte function. Assessing Citrulline levels is also relevant for monitoring the adverse effects of chemotherapy and radiotherapy on the intestinal mucosa (mucositis), intestinal Graft-Versus-Host Disease (GVHD) following hematopoietic stem cell transplantation, and systemic inflammatory states (low levels due to intestinal damage).
• Nitric Oxide Production in Cardiovascular and Neurological disorders: We offer an ELISA pack to determine the global arginine bioavailability ratio (arginine/[ornithine + citrulline]), which can be used to infer nitric oxide production in the context of cardiovascular diseases involving endothelial dysfunction, and neurological disorders associated with impaired NO synthesis.
• Renal Insufficiency: Kidney disorders may reduce arginine synthesis from citrulline, leading to high plasma citrulline concentrations
• Tumor Metabolism and Immune Evasion: Measuring citrulline can be of interest to understand how tumors alter amino acid metabolism and protein structures (citrullination) to escape immune control.
• Evaluation of Citrulline supplementation: For individuals taking citrulline supplements to enhance exercise performance or support cardiovascular health, our Citrulline ELISA kit can help monitor plasma levels to optimize dosing.

Our ELISA kits to assess arginine metabolism: