Biomaterial Database

Angiotensin II in human cerebrospinal fluid may be an immunoassay artifact. 1980

P F Semple, and W A Macrae, and J J Morton

1. Concentrations of angiotensin II (ANG II) were measured by radioimmunoassay in cerebrospinal fluid and plasma from neurosurgical patients and patients having spinal anaesthesia. Cerebrospinal fluid concentrations of renin, renin substrate and ANG I were also measured. 2. Cerebrospinal fluid concentrations of ANG II measured with antiserum 30/VI were low in neurosurgical patients (mean 6 pmol/l, range < 2 - 12 pmol/l, n = 7) and lower in spinal anaesthesia patients (mean 1 pmol/l, range < 2 - 4 pmol/l, n = 14) and unrelated to concurrent plasma concentrations of ANG II. 3. A second more sensitive immunoassay with ANG II antiserum 9/P gave higher cerebrospinal fluid concentrations of ANG II in spinal anaesthesia patients (mean 15 +/- 1 pmol/l, n = 7, P < 0.01). 4. Paper chromatography showed that the ANG II immunoreactive material measured with antiserum 9/P was not ANG I, ANG II, ANG II-(2-8), ANG II-(3-8) or ANG II-(4-8). 5. The concentration of ANG I in cerebrospinal fluid was low (4 +/- 0.04 pmol/l, n = 7). No renin was detected (n = 32) and the concentration of renin substrate was 45 +/- 2.6 nmol/l (n = 24). 6. Much of the immunoreactive ANG II in human cerebrospinal fluid is an immunoassay artifact.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D011863	Radioimmunoassay	Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.	Radioimmunoassays
D012083	Renin	A highly specific (Leu-Leu) endopeptidase that generates ANGIOTENSIN I from its precursor ANGIOTENSINOGEN, leading to a cascade of reactions which elevate BLOOD PRESSURE and increase sodium retention by the kidney in the RENIN-ANGIOTENSIN SYSTEM. The enzyme was formerly listed as EC 3.4.99.19.	Angiotensin-Forming Enzyme,Angiotensinogenase,Big Renin,Cryorenin,Inactive Renin,Pre-Prorenin,Preprorenin,Prorenin,Angiotensin Forming Enzyme,Pre Prorenin,Renin, Big,Renin, Inactive
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000368	Aged	A person 65 years of age or older. For a person older than 79 years, AGED, 80 AND OVER is available.	Elderly
D000803	Angiotensin I	A decapeptide that is cleaved from precursor angiotensinogen by RENIN. Angiotensin I has limited biological activity. It is converted to angiotensin II, a potent vasoconstrictor, after the removal of two amino acids at the C-terminal by ANGIOTENSIN CONVERTING ENZYME.
D000804	Angiotensin II	An octapeptide that is a potent but labile vasoconstrictor. It is produced from angiotensin I after the removal of two amino acids at the C-terminal by ANGIOTENSIN CONVERTING ENZYME. The amino acid in position 5 varies in different species. To block VASOCONSTRICTION and HYPERTENSION effect of angiotensin II, patients are often treated with ACE INHIBITORS or with ANGIOTENSIN II TYPE 1 RECEPTOR BLOCKERS.	Angiotensin II, Ile(5)-,Angiotensin II, Val(5)-,5-L-Isoleucine Angiotensin II,ANG-(1-8)Octapeptide,Angiotensin II, Isoleucine(5)-,Angiotensin II, Valine(5)-,Angiotensin-(1-8) Octapeptide,Isoleucine(5)-Angiotensin,Isoleucyl(5)-Angiotensin II,Valyl(5)-Angiotensin II,5 L Isoleucine Angiotensin II,Angiotensin II, 5-L-Isoleucine
D000808	Angiotensinogen	An alpha-globulin of about 453 amino acids, depending on the species. It is produced by the liver in response to lowered blood pressure and secreted into blood circulation. Angiotensinogen is the inactive precursor of the ANGIOTENSINS produced in the body by successive enzyme cleavages. Cleavage of angiotensinogen by RENIN yields the decapeptide ANGIOTENSIN I. Further cleavage of angiotensin I (by ANGIOTENSIN CONVERTING ENZYME) yields the potent vasoconstrictor octapeptide ANGIOTENSIN II; and then, via other enzymes, other angiotensins also involved in the hemodynamic-regulating RENIN-ANGIOTENSIN SYSTEM.	Hypertensinogen,Renin-Substrate,SERPINA8,Proangiotensin,Renin Substrate Tetradecapeptide,Serpin A8,Renin Substrate,Tetradecapeptide, Renin Substrate