The biological function of nerve-growth factor (NGF) is initiated by specific interactions with extracellular sites of two classes of NGF receptors (NGFR). The receptor expression is shown to be induced by neurodegenerative diseases such as Alzheimer. and Parkinson's disease. The extracellular region of NGFR is found to be truncated (T-NGER) and diffused into biological t1uids such as urine. The determination of T-NGFR in the biological fluids, therefore, may be used as a marker to determine the stage of neurodegenerative diseases.Objective: This study was designed to develop a t1uororeceptor assay (FRA) for determinaion of T-NGFR in urine. Methods: NGF was purified from the submaxillary glands of mice and labeled by t1uoresein isothiocyanate (F-NGF). Then antiserum against F-NGF was raised in rabbit.Results: When F-NGF was incubated with rabit anti-flurescein serum, fluorescein intensity of F-NGF was quenched significantly. However addition of urine sample in the assay mixture reversed the fluourscence intensity, to a level near to that of F-NGF alone. It appears that binding of the protein moiety of F-NGF with urinary T-NGFR prevents subsequent binding of the t1uorescein groups by anti-fluorescein. The results indicated that the t1uorescence intensity of the assay mixture directly ret1ects the amount of T-NGFR in the urine. Conclusion: It is concluded that the avilability of fluorescein - labeled NGF and anitibody against it permits measurement of T-NGFR in urine. The quality of the assay and it's preliminary clinical application for nerurodegenerative diseases have been evaluated.
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مقاله پژوهشی |
دریافت: 1387/8/21 | پذیرش: 1378/12/25 | انتشار: 1378/12/25