ISSN:
1052-9306
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
In a study to test the hypothesis that defects in the metabolism of neuropeptides might be a contributing factor to human anterior pituitary tumor formation, the proenkephalin A, proopiomelanocortin (POMC), and tachykinin systems, which produce methionine enkephalin (ME), β-endorphin (BE), and substance P (SP), respectively, were measured in patients who had a wide variety of pituitary tumors. Mass spectrometry was used to optimize the level of molecular specificity of the ME and BE analytical measurements, and radioimmunoassay was used to measure SP-like immunoreactivity (SP-li). Compared to data obtained from pituitaries from post-mortem controls, the non-secreting tumors contained a significantly lower amount of the POMC neuropeptide, BE. The lower ME level was not significant. However, two adrenocorticotrophic hormone (ACTH)-secreting tumors contained ME, BE, and SP-li amounts that were much higher than both the controls and nonsecreting tumors. These data suggest that a hypometabolism of the POMC precursor may be operating in non-secreting tumors, and that a hypermetabolism of the proenkephalin A, POMC, and tachykinin precursors may be operating in two ACTH-secreting tumors. These data demonstrate that mass spectrometry plays a critical role in the study of human pituitary tumors.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bms.1200220112
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