Intended use

The Euro Diagnostica angiotensin II kit contains reagents and instructions for the measurement of angiotensin II in plasma. After extraction the angiotensin II concentrations are measured by radioimmunoassay (RIA).

For professional use witin a laboratory.

This product is also available as research use only. Product code: RB 320 RUO

For complete product description, claims and use, please refer to the Instructions For Use. Contact your local representative for availability in your country.

Background

Angiotensin II is the biologically active product of the renin-angiotensin system.

The octapeptide angiotensin II (molecular weight 1046) is the strongest physiological vasoconstrictor known. From a large protein precursor (pre-proangiontesinogen) synthesized in the liver it is liberated in a series of proteolytic steps catalyzed by enzymes from various tissues. Angiotensin II is very short-lived in the plasma: Once generated from angiotensin I, it is degraded further into physiologically inactive peptides by various plasma peptidases, at a plasma half life of less than a minute.

Since the generation of angiotensin II from angiotensinogen via angiotensin I is strongly affected by changes of the renin activity, all external factors influencing renin activity are to be carefully considered: renin activity is elevated during pregnancy, after sodium depletion, in upright position, and under the influence of a range of drugs, e.g. oral contraceptives, adrenalin, antihypertensive vasodilatators, diuretics, high doses of spironalactone and progesterone. Factors decreasing renin activity are: horizontal position, increased sodium uptake, a-methyl-DOPA, L-DOPA, propranolol, reserpin, clonidin and old age. Renin activity is also subject to a diurnal rhythm with peak values in the morning.

The angiotensin II radioimmunoassay is useful in the study of hypertension monitoring and treatment.

Technical information

After extraction of the plasma samples, angiotensin II is assayed by a competitive radioimmunoassay. This radioimmunoassay is using a rabbit anti-angiotensin II antiserum and a radio-iodinated angiotensin II tracer. Bound and free phases are separated by a second antibody bound to solid phase particles, followed by a centrifugation step. The radioactivity in the bound fractions is measured and a typical standard curve can be generated.

Kit components and storage of reagents

The reagents provided in each kit are sufficient for 100 tubes.

1. Anti-angiotensin II (Reagent A), Nr. of Vials: 1, Containing:  Lyophilized anti-angiotensin II, (Rabbit) for 100 tubes. Colour: Yellow.
2. ¹²⁵I-angiotensin II (Reagent B), Nr. of Vials: 1, Containing:  56 KBq or 1.5 micro Ci. Lyophilized. Specific activity: 62-77 MBq/nmol (1700-2100 micro Ci/nmol). Colour: Blue.
3. Double antibody solid phase (Reagent C), Nr. of Vials: 1, Containing:  Goat anti-rabbit IgG’s bound to solid phase.11 mL suspension.
4. Assay buffer  (Reagent D), Nr. of Vials: 2, Containing:  0.05 M phosphate buffer with 0.25% HSA, 0.25% EDTA disodium salt, 0.05% NaN₃, 500 KIU Trasylol/mL, pH 7.4. 2 x 50 mL (liquid).
5. Angiotensin II standard 300 pmol/L (Reagent E), Nr. of Vials: 1, Containing: 5.0 mL angiotensin II standard, 300 pmol/L. Lyophilized in assay buffer.
6. Angiotensin II, low control (Reagent F), Nr. of Vials: 1, Containing: 2.0 mL lyophilized angiotensin II control, low level.
7. Angiotensin II, high control (Reagent G), Nr. of Vials: 1, Containing: 2.0 mL lyophilized angiotensin II control, high level.

Shelflife and storage

This kit is stable until the stated expiry date if stored as specified.

Upon receipt of the kit, all reagents should be stored at 2-8°C.