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Abstract  

The iodination and separation of various diagnostically and/or experimentally important peptides including (Tyr1)-somatostatin-14, rat Tyr-a-calcitonin gene-related peptide (23-37), motilin and vasoactive intestinal peptide, furthermore bovine serum albumin are described. All species were iodinated by the iodogen method. The 125I-labeled peptide products were separated by reversed-phase HPLC, the specific activities of mono-iodinated forms are near identical with the theoretical value. The labeled bovine serum albumin was separated by Sephadex G-100 gel filtration.

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Abstract  

In the present paper the development and application of a novel gastrin radioimmunoassay (RIA) are described. 125I-labeling of non-sulphated human gastrin-17 (nshG-17) was performed by the iodogen method and the mono-iodinated hormone, as RIA tracer, was separated by reversed-phase high performance liquid chromatography (HPLC). Serum gastrin levels were measured in response to intravenous application of isoproterenol, a non-selective beta and phenylephrine, a selective alpha-1 receptor agonist using a newly developed method specific for the C-terminal part of the hormone in rats. Isoproterenol at clinically relevant doses elicited a significant increase in serum gastrin concentration in a dose-dependent fashion, whereas phenylephrine was without effect.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
J. Németh
,
B. Jakab
,
R. Józsa
,
T. Hollósy
,
A. Tamás
,
A. Lubics
,
I. Lengvári
,
P. Kiss
,
Zs. Oberritter
,
B. Horváth
,
Z. Szilvássy
, and
D. Reglődi

Abstract  

Pituitary adenylate cyclase activating polypeptide (PACAP) is a widely distributed neuropeptide that has two molecular forms with 38 and 27 amino acid residues. The aim of the present study was to develop a new, highly specific PACAP-27 assay to investigate the quantitative distribution of PACAP-27 in the central nervous system of various vertebrate species applying the same technical and experimental conditions. Our results show that the antiserum used turned to be PACAP-27 specific. The average ID50 value was 51.5±3.6 fmol/ml and the detection limit was 2 fmol/ml. PACAP-27 immunoreactivity was present in the examined brain areas, with highest concentration in the rat diencephalon and telencephalon. Swine and pigeon brain also contained significant amount of PACAP-27. Our results confirm the previously described data showing that PACAP-38 is the dominant form of PACAP in vertebrates, since PACAP-38 levels exceeded those of PACAP-27 in all examined brain areas. Furthermore, our study describes for the first time, the comparative quantitative distribution of PACAP-27 and-38 in the swine and pigeon brain.

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