title: Leu-enkephalin-like immunoreactivity in proliferative lesions of the human adrenal medulla and extra-adrenal paraganglia.
abstract: Leu-enkephalin, a potent, endogenous, opiate-like regulatory peptide, is present in a subpopulation of normal adrenal medullary cells and in a spectrum of proliferative lesions of adrenal and extra-adrenal chromaffin cell origin. The presence, extent, and intensity of leu-enkephalin-like immunoreactivity is variable in normal and pathological states. While areas of diffuse medullary hyperplasia consistently exhibited leu-enkephalin-like immunoreactivity, approximately 50% of hyperplastic medullary nodules, pheochromocytomas, and paragangliomas were positively stained. Tumors of neuroblastic origin, on the other hand, did not contain leu-enkephalin-like immunoreactivity. Variations in leu-enkephalin-like immunoreactivity may be related to aberrations of feedback mechanisms, multicentric origins of lesions from chromaffin cells with or without the capacity for leu-enkephalin synthesis, or to a variety of other mechanisms, including defective innervation of hyperplastic and neoplastic chromaffin cells. The results of these studies indicate that leu-enkephalin-like immunoreactivity is a useful tissue marker for the demonstration of chromaffin cell hyperplasia and neoplasia and may also prove to be an important clinical marker for the assessment of chromaffin cell hyperfunction.
mesh_terms: D000310:Adrenal Gland Neoplasms / Q000032:analysis* / Q000473:pathology; D000313:Adrenal Medulla / Q000032:analysis / Q000473:pathology*; D004743:Enkephalin, Leucine / Q000032:analysis*; D005729:Ganglioneuroma / Q000032:analysis; D006651:Histocytochemistry; D006801:Humans; D006965:Hyperplasia; D007124:Immunoenzyme Techniques; D009447:Neuroblastoma / Q000032:analysis; D010673:Pheochromocytoma / Q000032:analysis* / Q000473:pathology
chemical_list: D004743:Enkephalin, Leucine