Neuroendocrine Assay Core

The Neuroendocrine Assay Core provides the Center with state of the art resources and expertise related to the measurement of neuroendocrine mediators involved in central and peripheral signaling pathways and interpretation of results. The Core utilizes much of the existing equipment and resources that are available in the NIH-funded CURE: Digestive Diseases Research Center/ Antibody and Radioimmunoassay Core (G. Ohning, P.I.) and Peptide Biochemistry and Molecular Probes Core laboratories (J. Reeve, P.I.). The Core has the capability to perform radioimmunoassay, HPLC, and MDLC measurement of serum and CSF levels of neuroendocrine mediators in samples obtained from human and animal subjects.

Services

Catecholamine assays of plasma using HPLC with electrochemical detection have been established and extraction and assay conditions for tissue catecholamine levels are being determined. Assays for serum, urine, and salivary levels of ACTH, cortisol/corticosterone, catecholamines, oxytocin, and pancreatic polypeptide are currently available to investigators. Corticosterone assays using EIA have been performed and samples are being collected, logged, and stored for ACTH and cortisol assays. Freezer space has been identified for collection of samples for batch measurements once cohorts of patients have been completed. Use of batch measurements will further reduce assay costs for investigators and will be employed unless more preliminary data is required. Continued and expanded utilization of tissue processing, standard staining and immunohistochemical measurements is ongoing. Tissue processing and paraffin embedding/sections can be provided to investigators with H&E staining for histological evaluation of tissue injury and immunostaining for NPY receptor and Mast cell protease as markers of neuronal and inflammatory activity.

Additional or expanded services include immunohistochemical measurement of markers of inflammation, neuroendocrine peptides and receptors in tissues. Antibodies to NPY1 and NPY1-receptor (1) are available through the CURE Antibody/RIA Core laboratory and have been used to localize and quantify levels in colon tissue for center investigators. Mast cells measurements in tissue specimens can be performed using mast cell protease immunohistochemistry (2). Additional immunohistochemical and plasma/tissue level measurements requested include neutrophil myeloperoxidase, TNF-a , IL-6 , IL-10 (3,4), and additional cytokine assays and these requests are being developed using antibodies from commercial sources. Immunohistochemical staining and RIA measurements using CURE Antibody Core laboratory reagents are also available to Center investigators.

The Core laboratory provides assistance and teaching to Center investigators regarding sample procurement and preparation, including collection of plasma, saliva, urine, and tissue specimens. Equipment in the Core Lab is available to Center investigators to reduce the time and cost associated with sample preparation. Investigators and/or their personnel can be trained in use of the Tissue Tek VIP tissue processor, Tissue-Tek embedding console, and microtome for processing specimens. Technical assistance is provided for investigators in performing these functions as requested. Tissue preparation for frozen sections is also available within the P.I.'s laboratory and can be used if required for immunohistochemical methods that cannot be performed in paraffin sections.

References cited:
1) Kopp,J.; Xu,Z.Q.; Zhang,X.; Pedrazzini,T.; Herzog,H.; Kresse,A.; Wong,H.; Walsh,J.H.; Hokfelt,T. "Expression of the neuropeptide Y Y1 receptor in the CNS of rat and of wild-type and Y1 receptor knock-out mice. Focus on immunohistochemical localization." Neuroscience 111:443-532 (2002)
2) Huntley JF, Mackellar A, Miller HR. "Altered expression of mast cell proteases in the rat. Quantitative and immunohistochemical analysis of the distribution of rat mast cell proteases I and II during helminth infection." APMIS 101:953-62 (1993)

Animal Models Core
Health Outcomes Core
Neuroimaging Core
Psychophysiology and Pain Assessment Core