Code Details for Lab and Clinical Services
ISI Order Code: AGT
CPT Code: 83520
Clinical Significance of Angiotensinogen
Angiotensinogen is a liver-derived plasma protein and the precursor of the renin–angiotensin–aldosterone system (RAAS), which regulates blood pressure, fluid balance, and vascular tone. It is cleaved by renin to initiate angiotensin II formation, leading to vasoconstriction and aldosterone release. Plasma levels increase with estrogen exposure (pregnancy, oral contraceptives), inflammation, glucocorticoid excess, and hyperthyroidism, potentially enhancing RAAS activity. Genetic variation in the angiotensinogen gene has been linked to hypertension risk. Reduced levels may indicate impaired hepatic synthetic function.
Reference Range, Procedure & Expected Results
Reference Range:
13.9–75.9 µg/mL
Procedure:
Angiotensinogen is measured by an immunoassay.
Expected Turnaround Time:
10 Business Days
Turnaround time is defined as the usual number of days from the date of receipt of a specimen for testing to when the result is released to the ordering facility.Report: Sample Report
Patient Preparation Guidelines
Medications affecting the renin–angiotensin system may influence results and should be reviewed by the clinician.
Specimen Collection:
3mL EDTA plasma should be collected and separated as soon as possible. Freeze EDTA plasma immediately after separation. Minimum specimen size is 1.0
Important Precautions
For Research Use Only. Not for use in diagnostic procedures.
Rejection Criteria:
- Gross hemolysis/lipemia/icteric
Shipping and Handling Instructions for GIP Assay Specimens
Shipping Instructions:
Ship specimens frozen in dry ice.
Research & Scientific References
- 1 Hall, J. E., & Guyton, A. C. (2021). Guyton and Hall textbook of medical physiology (14th ed.). Elsevier.
- 2 Jameson, J. L., Fauci, A. S., Kasper, D. L., Hauser, S. L., & Loscalzo, J. (2022). Harrison’s principles of internal medicine (21st ed.). McGraw-Hill.
- 3 Fyhrquist, F., & Saijonmaa, O. (2008). Renin–angiotensin system revisited. Journal of Internal Medicine, 264(3), 224–236. https://doi.org/10.1111/j.1365-2796.2008.01981.x
- 4 Kobori, H., Nangaku, M., Navar, L. G., & Nishiyama, A. (2007). The intrarenal renin–angiotensin system: From physiology to pathobiology. Pharmacological Reviews, 59(3), 251–287. https://doi.org/10.1124/pr.59.3.3