Angiotensin II (RIA)

Test ID: 


CPT code:


Clinical Use:

The renin-angiotensin aldosterone hormonal cascade that regulates blood pressure and water (fluid) balance begins with the biosynthesis of renin by the juxtaglomerular cells that line the afferent (and occasionally efferent) arteriole of the renal glomerulus.1,2 A drop in blood pressure decreases the perfusion of the juxtaglomerular apparatus, resulting in the release of the enzyme renin. Renin proceeds to cleave angiotensinogen to produce angiotensin I. Angiotensin I is in turn converted to angiotensin II by angiotensin-converting enzyme (ACE), which is found mainly in lung capillaries. Angiotensin II is the major bioactive product of the renin-angiotensin system, binding to receptors on intraglomerular mesangial cells, causing these cells to contract along with the blood vessels surrounding them and causing the release of aldosterone from the adrenal cortex. Angiotensin II has multifaceted effects on aldosterone secretion, vasoconstriction, sodium reabsorption, and fluid volume, all of which serve to raise blood pressure. Laboratory studies with cultured cardiomyocytes have implicated angiotensin as a direct cause of left ventricular hypertrophy associated with hypertension. Angiotensin II also inhibits renin release by the kidney via a feedback mechanism.

Specimen Type:

Plasma, frozen

Requested Volume: 

3 mL

Minimum Volume: 

1.5 mL (Note: This volume does not allow for repeat testing.)

Container Type: 

Patient must not have received radioactive substances 24 hours prior to test. Patient should be fasting.Patient Preparation: 


 Using a chilled 6-mL lavender-top (EDTA) tube collect a whole blood specimen. Mix the specimen several times by inverting the EDTA collection tube. After removing the cap from the EDTA draw tube, take one of the sterile, Beral pipettes (from under the gray foam), and add 0.25 mL Trasylol® to the EDTA tube. Recap the EDTA tube and invert several times to mix well. Centrifuge the EDTA tube to separate the plasma from the cells, and immediately transfer the plasma into one of the brown screw-cap transfer tubes provided in the kit. There should be a “Trasylol® Added” label affixed to the brown transport tubes. Cap and freeze the labeled transport tube containing the EDTA plasma with Trasylol® added. To avoid delays in turnaround time when requesting multiple test on frozen samples, please submit separate frozen specimens for each test requested.

Storage Instructions:


Stability Requirements:



Room temperature

1 hour


1 hour


14 days

Freeze/thaw cycles

Stable x3

Rejection Criteria

Sample not collected with Trasylol®; sample not submitted in tube with Trasylol label, gross hemolysis; recently administered radioisotopes; specimen not received frozen; serum, sodium citrate, or heparinized plasma specimen; lipemia

Return Back to Test Directory

MCI Diagnostic

Providing top patient care with fast results. 

7018 South Utica Avenue

Tulsa, Oklahoma 74136

Hours of Operation

Mon – Sat: 7AM-11PM

Sun: 7AM-3PM

Government Contract

Mon – Sat: 7AM-11PM

Sun: 7AM-3PM


Mon – Sat: 7AM-11PM

Sun: 7AM-3PM

Thank you for uploading your files. Your upload has been submitted successfully.