Clinical Significance:
Prostaglandins are fatty acids derived from arachidonic acid metabolism. They are closely related to the Thromboxanes and Leukotrienes. Prostaglandin E1 is derived mainly from Prostaglandin H1, and is metabolized to Prostaglandin F1a. Prostaglandin E1 is excreted directly into the urine. Prostaglandin E1 relaxes the circular muscle of the gut in opposition to Prostaglandin F2a, and also relaxes the lower esophageal sphincter. Prostaglandin E1 reduces gastric secretion preventing the formation of ulcers. Prostaglandin E1 is also a potent inhibitor of platelet aggregation. Prostaglandin E1 stimulates accumulation of cyclic AMP and can stimulate thyroid activity in a manner similar to that of TSH. Elevated leves have been found in patients with tuberculosis, lung cancer, medullary carcinoma of the thyroid, carcinoid syndrome, neuroblastomas, and the Watery Diarrhea Syndrome. Prostaglandin E1 production and circulating levels are drastically suppressed by aspirin and indomethacin.
Reference Range:
*Reported per liter basis. No reference intervals available for this test.
Procedure:
Urine Prostaglandin E1 is measured by direct EIA/ELISA.
Patient Preparation:
Patient should not be on aspirin, indomethacin, or anti-inflammatory medications, if possible, for at least 48 hours prior to collection of specimen.
Specimen Collection:
5-10mL of a random urine specimen should be collected and frozen immediately. Specimen must remain frozen prior to and during shipping. 24-hour urine collections are not acceptable. Rejection criteria include: room temperature, thawed or refrigerated specimens or 24-hour urine collections.
Shipping Instructions:
Ship specimens frozen in dry ice.
References:
1. JS Redfern and M Feldman. Role of Endogenous Prostaglandins in Preventing Gastrointestinal Ulceration: Induction of Ulcers by Antibodies to Prosta-glandins. Gastroenterology 96: 596, 1989.
2. MJ Dunn and EJ Zambraski. Renal Effects of Drugs that Inhibit Prostaglandin Synthesis. Kidney International 18: 609, 1980.