angiotensin-1/renin activity in plasma

Indications

• the captopril test uses plasma renin levels before & after administration of captopril
• differentiation of primary & secondary hyperaldosteronism
• assessment of renovascular hypertension

Reference interval

• adults
  • normal diet
    • supine: 0.3-1.9 ng/mL/hour
    • upright: 0.2-3.6 ng/mL/hour
  • low sodium diet:
    • supine: 0.9-4.5 ng/mL/hour
    • upright: 4.1-9.1 ng/mL/hour
  • diuretics & low sodium diet:
    • 6.3-13.5 ng/mL/hour
• infants
  • 0-1 weeks: < 40 ng/mL/hour
  • 2-4 weeks: < 175 ng/mL/hour
• 18-39 years of age
  • Na+-depleted: 10.8 (2.9-24.0) ng/mL/hour
  • Na+-repleted: 1.0 (<0.6-4.3) ng/mL/hour
• > 39 years of age
  • Na+-depleted: 5.9 (2.0-10.8) ng/mL/hour
  • Na+-repleted: 1.0 (<0.6-3.0) ng/mL/hour

Increases

• pharmaceutical_agents
  • in vivo effects
    • ACE inhibitors, chlorpropamide, diazoxide, estrogens, guanethidine (with Na+ depletion), hydralazine, minoxidil, nifedipine, nitroprusside, K+ sparing diuretics, thiazides
• clinical disorders
  • with secondary hyperaldosteronism
    • hypertensive states
      • severe or malignant hypertension with or without unilateral kidney disease
      • renal parenchymal disease
      • renin-secreting tumors
      • oral contraceptive-induced hypertension
      • pheochromocytoma
    • edematous non-hypertensive states
      • cirrhosis
      • hepatitis
      • nephrosis
      • congestive heart failure
    • hypokalemic normotensive states
      • juxtaglomerular cell hyperplasia (Bartter's syndrome)
      • nephropathies with Na+ or K+ wastage
      • gastrointestinal disorders with electrolyte loss
  • without secondary hyperaldosteronism
    • adrenocortical insufficiency
    • K+ depletion state (gastrointestinal)
    • pregnancy
• cyroactivation of prerenin (chilled tubes)

Decreases

• pharmaceutical_agents
  • in vivo effects
    • beta blockers, angiotensin (IV), aspirin, carbenoxolone, clonidine, deoxycorticosterone, guanethidine (normal Na+), indomethacin, licorice, methyldopa, K+, prazosin, reserpine
• clinical disorders
  • with adrenocortical disease
    • hypertensive states
      • primary hyperaldosteronism due to adrenal adenoma
      • bilateral adrenocortical hyperplasia
      • glucocorticoid-suppressible hyperaldosteronism
      • adrenal carcinoma with mineralocorticoid excess
      • adrenal enzymatic defects resulting in excess secretion of mineralocorticoids
  • without adrenocortical disease
    • hypertensive states
      • low-renin essential hypertension
      • renal parenchymal disease
      • Liddle's syndrome
    • normotensive states
      • renal parenchymal disease
      • autonomic disorders with postural hypotension
      • uninephrectomized subjects
      • hyperkalemia

Methods

• RIA for angiotensin-1
• plasma renin activity is measured indirectly by the ability of the patient's plasma to generate angiotensin-1*
• simultaneous measurement of 24 hour urine Na+ & creatinine & serum/plasma Na+, K+ & creatinine are recommended

   angiotensinogen   ----- renin ------>   angiotensin-1

Specimen

• plasma (Na2EDTA, Lavender top)
• place in ice water & centrifuge at 4 degrees C
• separate plasma at freeze promptly at -20 degrees C
• stable for up to 1 year

More general terms

• analyte ratio

Additional terms

• aldosterone in serum/plasma
• Aldosterone/Renin in serum/plasma
• angiotensin I
• captopril-renin stimulation test
• renin activity in renal vein
• renin-angiotensin-aldosterone axis
• renin; angiotensinogenase (REN)

Component of

• hypertension panel

Components

• angiotensin 1 in plasma
• renin in plasma

Patient information

angiotensin-1/renin activity in plasma patient information