Renin

Specimen:

10 mL blood in EDTA tube, transported immediately to the laboratory on melting ice.

Selective venous sampling from the vena cava and renal veins may be indicated.

Method:

Measurement of renin activity as angiotensin I generation from angiotensinogen.

Peripheral venous renin is usually assayed in conjunction with aldosterone The aldosterone/renin ratio is then calculated.

Reference Interval:

Depends on patient preparation, posture and drug therapy (eg, levels increased by diuretics, ACE inhibitors) - consult pathologist.

Application:

Investigation of hypertension when primary hyperaldosteronism or unilateral renal disease is suspected.

Assessing adequacy of mineralocorticoid replacement.

Management of congenital adrenal hyperplasia.

See also Aldosterone.

Interpretation:

High aldosterone/renin ratio suggests a mineralocorticoid abnormality.

High renin and aldosterone suggests a renal abnormality.

Lateralising studies are done in suspected unilateral renal ischaemia or renal artery stenosis.

In congenital adrenal hyperplasia, excessive levels indicate inadequate mineralocorticoid replacement.

Reference:

Lins P-E and Adamson U. Acta Endocrinol 1986; 113: 564-569.