Type of test Blood

 Normal findings

 Chromogranin A: ≤ 225 ng/mL

Serotonin: ≤ 230 ng/mL

Test explanation and related physiology

 Serotonin is synthesized from the essential amino acid tryptophan chiefly in the gastrointestinal (GI) enterochromaffin (EC) cells. Many different stimuli can release serotonin from EC-cells. After it is secreted, in concert with other gut hormones, serotonin increases GI blood flow, motility, and fluid secretion. On the first pass through the liver, 30% to 80% of serotonin is metabolized, predominately to 5-hydroxyindoleacetic acid (5-HIAA) (p. 531), which is then excreted by the kidneys.

The main diseases that may be associated with measurable increases in serotonin are neuroectodermal tumors, in particular tumors arising from EC cells. These tumors are collectively referred to as carcinoids. Most symptoms of carcinoid tumors are caused by elevated serotonins (carcinoid syndrome). The carcinoid syndrome consists of flushing, diarrhea, right-sided valvular heart lesions, and bronchoconstriction.

Diagnosis of carcinoid tumors with symptoms suggestive of carcinoid syndrome rests on measurements of serum serotonin, urinary 5-HIAA, and serum chromogranin A (a peptide that is cosecreted alongside serotonin by the neuroectodermal cells). Metastasizing midgut carcinoid tumors usually produce blood or serum serotonin concentrations greater than 1000 ng/mL. It is only after carcinoid tumors metastasize that serotonin becomes detectable.

Disease progression can be monitored in patients with serotonin-producing carcinoid tumors by measurement of serotonin or chromogranin A in blood.

Chromogranin A also acts as a useful cancer tumor marker (p. 196) for other neuroendocrine neoplasms, including carcinoids, pheochromocytomas, neuroblastomas, medullary thyroid carcinomas, some pituitary tumors, functioning and nonfunctioning islet-cell tumors, and other amine precursor uptake and decarboxylation (APUD) tumors. It can also serve as a sensitive means for detecting residual or recurrent disease in treated patients. Carcinoid tumors, in particular colon and rectal carcinoids, almost always secrete chromogranin A.

Interfering factors

* Drugs that may cause increased serotonin levels include lithium, monoamine oxidase inhibitors, methyldopa, morphine, and reserpine.

* Drugs that decrease serotonin levels include selective serotonin reuptake inhibitors (e.g., fluoxetine).

 Procedure and patient care

• See inside front cover for Routine Blood Testing.

 • Fasting: no

 • Blood tube commonly used: red

Abnormal findings

 Increased levels

- Carcinoid tumors

- Neuroendocrine tumors

- Pheochromocytoma

- Small cell lung cancer

اخر الاخبار

اخبار العتبة العباسية المقدسة

شعبة الخطابة تقيم مجلس عزاء بذكرى شهادة الإمام الحسن العسكري (عليه السلام)

قسم الشؤون الطبية يُنهي استعداداته لإحياء شهادة الإمام الحسن العسكري (عليه السلام) في سامراء

بالصور.. المؤمنون يتوافدون إلى سامراء لإحياء ذكرى شهادة الإمام الحسن العسكري (عليه السلام)

العتبة العباسية المقدسة تنشر لافتات العزاء بذكرى شهادة الإمام الحسن العسكري (عليه السلام)

المزيد

الآخبار الصحية

لا تبحث عن الدواء.. هذه الأطعمة كفيلة بإيقاف ألم الرأس

لا تترك زجاجة الماء في السيارة.. احذر شربها

عادة يومية.. كيف يؤثر تصفيف الشعر على جهازك التنفسي؟

احذر هذه الأطعمة.. تسرع الشيخوخة وتفقد بشرتك شبابها

المزيد

الآخبار التكنلوجية

الأوكتان وتأثيره: نصائح لحماية محرك سيارتك بكفاءة وأمان

حرب شهر سبتمبر تشتعل.. ماذا في جعبة أبل وسامسونغ؟

واتساب يطلق ميزة لتعديل الرسائل بالذكاء الاصطناعي

على الكوكب الأحمر.. ناسا تعثر على "قبعة الساحرة"

المزيد

مواضيع ذات صلة

Quality Specifications of Troponin Measurement Methods

Clinical Relevance of Troponins Measurement

Hyperkalemia

sickle cell screen (Sickledex, Hemoglobin [Hgb] S test)

sexually transmitted disease testing (STD testing)

Hypokalemia

Hypernatremia

Hyponatremia

semen analysis (Sperm count, Sperm examination)

rubella antibody test (German measles test)

ribosome P antibodies (Ribosomal P Ab, Anti–ribosome P antibodies)

Water Balance