Molecular characterization of immunoreactivities of peptides derived from chromogranin A (GE-25) and from secretogranin II (secretoneurin) in human and bovine cerebrospinal fluid.
Chromogranin A and secretogranin II are members of the so-called chromogranins, the acidic proteins stored in neuroendocrine large dense-core vesicles. We characterized chromogranin A and secretogranin II immunoreactivities in cerebrospinal fluid by radioimmunoassays using synthetic peptides derived from these components (GE-25 for chromogranin A and secretoneurin for secretogranin II). In lumbar cerebrospinal fluid, high levels (more than 1000 fmol/ml) of these two components were found, whereas in ventricular cerebrospinal fluid the secretoneurin levels were relatively low. The cerebrospinal fluid/serum ratio for secretoneurin was close to 170. High-performance liquid chromatography revealed that in both cerebrospinal fluid and extracts from human brain secretoneurin was the predominant immunoreactive component. In cerebrospinal fluid chromogranin A immunoreactivity was present as intermediate-sized peptides with little intact chromogranin A and free GE-25 peptide. In human brain samples smaller peptides including GE-25 were more predominant. Analogous findings for secretoneurin and chromogranin A were obtained for bovine brain samples. We can conclude that chromogranins are present in cerebrospinal fluid in concentrations much higher than those of classical neuropeptides also stored in large dense-core vesicles. Therefore, their degree of proteolytic processing can be analysed with small samples of cerebrospinal fluid. A possible disturbance of proteolytic processing in large dense-core vesicles in various pathological conditions can now be discovered.
Kirchmair
R
R
Department of Pharmacology, University of Innsbruck, Austria.
Benzer
A
A
Troger
J
J
Miller
C
C
Marksteiner
J
J
Saria
A
A
Gasser
R W
RW
Hogue-Angeletti
R
R
Fischer-Colbrie
R
R
Winkler
H
H
D000328:Adult; D000368:Aged; D000375:Aging / Q000378:metabolism; D000818:Animals; D002417:Cattle; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D053379:Chromogranin A; D002864:Chromogranins / Q000134:cerebrospinal fluid*; D006801:Humans; D008875:Middle Aged; D009479:Neuropeptides / Q000134:cerebrospinal fluid*; D011863:Radioimmunoassay; D053381:Secretogranin II; D012727:Sex Characteristics; D013373:Substance P / Q000134:cerebrospinal fluid
C506150:CHGA protein, human; D053379:Chromogranin A; D002864:Chromogranins; D009479:Neuropeptides; D053381:Secretogranin II; C081159:secretoneurin; D013373:Substance P