Nitric Oxide Metabolites
Nitric Oxide Metabolites Overview Nitric oxide metabolites measure stable breakdown products of nitric oxide (NO), primarily nitrite (NO₂⁻) and nitrate (NO₃⁻), which reflect systemic NO production from endothelial, neuronal, and immune cells. Nitric oxide serves as a key vasodilator, neurotransmitter, and antimicrobial defense molecule; its metabolites indicate endothelial function, inflammation, and oxidative stress balance. Elevated […]
Norepinephrine
Norepinephrine Overview Norepinephrine measures a catecholamine neurotransmitter and hormone synthesized in sympathetic nerve terminals and the adrenal medulla that mediates the fight-or-flight response through α- and β-adrenergic receptor activation. It increases heart rate, blood pressure, and vascular tone while redirecting blood flow to vital organs during stress. Elevated levels indicate pheochromocytoma, sympathetic overactivity, or critical […]
NT-proBNP
NT-proBNP Overview NT-proBNP measures the inactive N-terminal fragment of pro-brain natriuretic peptide, released from cardiac ventricular myocytes in response to volume expansion and pressure overload. This peptide counterregulates the renin-angiotensin-aldosterone system by promoting natriuresis, diuresis, and vasodilation while inhibiting cardiac fibrosis. Elevated levels indicate heart failure, cardiac strain, or myocardial injury; low levels effectively rule […]
Neutrophils
Neutrophils Overview Neutrophils measure the absolute number or percentage of circulating neutrophils, the most abundant white blood cell type that serves as the first line of defense against bacterial and fungal infections through phagocytosis and release of antimicrobial granules. These granulocytes migrate rapidly to infection sites, forming pus and contributing to acute inflammatory responses. Elevated […]
Oxidized LDL
Oxidized LDL Overview Oxidized LDL measures low-density lipoprotein particles chemically modified by reactive oxygen species, promoting foam cell formation and atherosclerotic plaque development. These modified lipoproteins trigger endothelial dysfunction, monocyte recruitment, and inflammatory responses central to atherogenesis. Elevated levels indicate increased oxidative stress and cardiovascular risk; low levels correlate with vascular protection. Clinically, oxidized LDL […]
Oxytocin
Oxytocin Overview Oxytocin measures a nonapeptide hormone synthesized in the hypothalamus and released from the posterior pituitary that mediates uterine contraction during labor and milk ejection during breastfeeding. It also functions as a neuromodulator influencing social bonding, trust, anxiety regulation, and pair bonding through central nervous system receptors. Clinical measurement primarily assesses deficiency states; elevated […]
Orotic Acid
Orotic Acid Overview Orotic acid measures an intermediate in pyrimidine biosynthesis that accumulates when the urea cycle enzyme ornithine transcarbamylase (OTC) is deficient or when pyrimidine synthesis is dysregulated. Normally converted to orotidine monophosphate by orotate phosphoribosyltransferase, excess orotic acid in urine indicates hereditary urea cycle disorders or hereditary orotic aciduria. Elevated urinary levels diagnose […]
Osmolality
Osmolality Overview Osmolality measures the concentration of osmotically active particles (electrolytes, glucose, urea) in blood plasma or urine, expressed as milliosmoles per kilogram of water. Plasma osmolality maintains cellular volume homeostasis through antidiuretic hormone (ADH) regulation of water balance; urine osmolality reflects renal concentrating ability. Elevated plasma osmolality indicates dehydration or solute excess (glucose, mannitol), […]
Osteocalcin
Osteocalcin Overview Osteocalcin measures a vitamin K-dependent protein secreted by osteoblasts during bone formation that binds calcium and incorporates into bone matrix, serving as a marker of bone turnover and mineralization. Carboxylated osteocalcin anchors in hydroxyapatite while undercarboxylated forms circulate and may influence insulin sensitivity and testosterone production. Elevated levels indicate high bone formation rates […]
Phosphorus
Phosphorus Overview Phosphorus, measured as inorganic phosphate in serum, is an essential mineral critical for bone mineralization, energy metabolism via ATP, and cellular signaling. It exists primarily as phosphate ions and is tightly regulated by kidneys, parathyroid hormone, and vitamin D. Elevated levels (hyperphosphatemia) may indicate kidney dysfunction, hypoparathyroidism, or tissue damage, while low levels […]
PSA
PSA Overview Prostate-specific antigen (PSA) is a glycoprotein enzyme produced primarily by prostate epithelial cells, measuring serum levels that reflect prostate gland activity and integrity. It functions in liquefying semen and is released into the bloodstream in small amounts, with elevations often indicating prostate cell disruption or proliferation. High PSA levels may signal prostate cancer, […]
Progesterone
Progesterone Overview Progesterone is a steroid hormone primarily produced by the ovaries, placenta, and adrenal glands, measuring levels that reflect ovarian function, pregnancy maintenance, and menstrual cycle phases. It plays a key role in preparing the uterine lining for implantation and sustaining early pregnancy by promoting endometrial growth and suppressing uterine contractions. Elevated levels indicate […]
Hematocrit
Hematocrit Overview Hematocrit measures the volume percentage of packed red blood cells in whole blood after centrifugation, reflecting erythroid mass and oxygen-carrying capacity. It correlates directly with hemoglobin concentration and varies with hydration status, altitude, and erythropoietic activity. Elevated levels indicate polycythemia (dehydration, hypoxia, myeloproliferative disorders), while low levels signal anemia from blood loss, hemolysis, […]
Hemoglobin
Hemoglobin Overview Hemoglobin measures the oxygen-carrying iron-containing protein within erythrocytes that reversibly binds oxygen in the lungs and delivers it to tissues. It exists primarily as HbA (α2β2 tetramers) in adults, with variants like HbF and HbA2 having diagnostic significance. Low levels (anemia) indicate blood loss, hemolysis, nutritional deficiency, or bone marrow failure, while high […]
IgE
IgE Overview IgE measures the concentration of immunoglobulin E, a class of antibody mainly produced by plasma cells in response to allergens, parasites, and some infections. IgE binds with high affinity to Fcε receptors on mast cells and basophils, triggering the release of histamine and other mediators during type‑I immediate hypersensitivity reactions. Elevated total or […]
IgG
IgG Overview IgG measures the concentration of immunoglobulin G, the most abundant antibody class in human serum, which is produced by B cells and plasma cells in response to antigen exposure. As the major circulating immunoglobulin, IgG provides long‑term humoral immunity by neutralizing pathogens, promoting opsonization, and activating complement. Low total IgG levels suggest humoral […]
Interleukin-6
Interleukin-6 Overview Interleukin‑6 (IL‑6) is a proinflammatory cytokine produced by immune cells (e.g., macrophages, dendritic cells), endothelial cells, adipocytes, and various tissues in response to infection, tissue injury, or inflammation. It stimulates the liver to produce acute‑phase proteins such as C‑reactive protein and fibrinogen, and also promotes T‑ and B‑cell activation, hematopoiesis, and bone metabolism. […]
Iron
Iron Overview Iron measures the concentration of this essential trace metal in blood, primarily bound to transferrin, and reflects circulating iron available for erythropoiesis. Iron is a key component of hemoglobin, myoglobin, and various metalloenzymes involved in oxygen transport and cellular respiration. Low serum iron can indicate iron deficiency anemia, chronic disease, or blood loss, […]
Insulin
Insulin Overview Insulin is a peptide hormone secreted by pancreatic beta cells that regulates carbohydrate, fat, and protein metabolism by promoting glucose uptake into muscle and adipose tissue and suppressing hepatic glucose production. It is a key determinant of fasting and postprandial blood glucose concentrations and reflects beta‑cell function and insulin sensitivity. Low fasting levels […]
JAK‑STAT Signaling Marker
JAK‑STAT Signaling Marker Overview JAK‑STAT signaling marker refers to readouts of activation in the Janus kinase–signal transducer and activator of transcription (JAK‑STAT) pathway, which mediates cellular responses to cytokines, growth factors, and hormones. The pathway is triggered when ligand‑bound receptors recruit JAKs that phosphorylate receptor chains; STATs are then recruited, phosphorylated, dimerize, and translocate to […]