Kit for the specific assay of angiotensin II

An anti-Angiotensin III antibody obtained by immunization of an animal with a peptide derivative of formula (amino acids 1-8 of SEQUENCE ID NO. 2)

• H-Arg-Val-Tyr-Ile-His-R.sub.1 -R.sub.2 -Cys-NH.sub.2
• in which
• R.sub.1 denotes a direct bond or a chain-link comprising 1 or 2 natural amino acids,
• R.sub.2 denotes a group of formula --NH--(CH.sub.2).sub.n --CO--, and
• n denotes an integer from 1 to 9 inclusive,
• wherein said peptide derivative is bound to a carrier protein, and wherein said anti-Angiotensin III antibody is specific for Angiotensin III and exhibits a cross-reactivity with Angiotensin II of less than 10%.

An anti-pentapeptide antibody obtained by immunization of an animal with a peptide derivative of formula (amino acids 3-8 of SEQUENCE ID NO. 2)

• H-Tyr-Ile-His-R.sub.1 -R.sub.2 -Cys-NH.sub.2
• in which
• R.sub.1 denotes a direct bond or a chain-link comprising 1 or 2 natural amino acids,
• R.sub.2 denotes a group of formula --NH--(CH.sub.2).sub.n --CO--, and
• n denotes an integer from 1 to 9 inclusive,
• wherein said peptide derivative is bound to a carrier protein, and wherein said anti-pentapeptide antibody is specific for a degradation pentapeptide having all but the two N-terminal amino acid residues of Angiotensin III, and exhibits a crossreactivity with Angiotensin II of less than 10%.

An anti-hexapeptide antibody obtained by immunization of an animal with a peptide derivative of formula (amino acids 2-8 of SEQUENCE ID NO. 2)

• H-Val-Tyr-Ile-His-R.sub.1 -R.sub.2 -Cys-NH.sub.2
• in which
• R.sub.1 denotes a direct bond or a chain-link comprising 1 or 2 natural amino acids,
• R.sub.2 denotes a group of formula --NH--(CH.sub.2).sub.n --CO--, and
• n denotes an integer from 1 to 9 inclusive,
• wherein said peptide derivative is bound to a carrier protein, and wherein said anti-hexapeptide antibody is specific for a degradation hexapeptide having all but the N-terminal amino acid residue of Angiotensin III, and exhibits a cross-reactivity with Angiotensin II of less than 10%.

An anti-Angiotensin I antibody obtained by immunization of an animal with a peptide derivative of formula (SEQUENCE ID NO. 3):

• H-Cys-R.sub.2 -R.sub.3 -Arg-Val-Tyr-Ile-His-Pro-Phe-His-Leu-OH
• in which
• R.sub.3 denotes a direct bond or a chain-link comprising 1 or 2 natural amino acids,
• R.sub.2 denotes a group of formula --NH--(CH.sub.2).sub.n --CO--, and
• n denotes an integer from 1 to 9 inclusive,
• wherein said peptide derivative is bound to a carrier protein, and wherein said anti-Angiotensin I antibody is specific for Angiotensin I and exhibits a cross-reactivity with Angiotensin II of less than 10%.

A method for the assay of Angiotensin II which comprises the steps of:

• a) incubating
• i) an anti-Angiotensin II antibody with a reaction medium comprising
• ii) an extract of a biological fluid,
• iii) labeled Angiotensin II, and
• iv) an anti-Angiotensin III antibody which is specific for Angiotensin III and exhibits a crossreactivity with Angiotensin II of less than 10%, at a temperature between 4.degree. C. and room temperature for 12 to 72 hours;
• b) separating labeled and unlabeled Angiotensin II bound to said anti-Angiotensin II antibody from said reaction medium;
• and
• c) measuring the amount of labeled Angiotensin II bound to said anti-Angiotensin II antibody to determine the amount of unlabeled Angiotensin II present in said extract.