alpha(1)-adrenergic receptors in human spinal cord: specific localized expression of mRNA encoding alpha(1)-adrenergic receptor subtypes at four distinct levels

alpha(1)-Adrenergic receptors (alpha(1)ARs) are important in lower urinary tract syndromes such as benign prostatic hypertrophy and bladder irritabili ty. Spinal cord alpha(1)ARs have been postulated to play a role in modulati ng these diseases, yet alpha(1)AR subtype (alpha(1a), alpha(1b), alpha(1d)) neuronal localization in human spinal cord has not been described. We ther efore tested the hypothesis that or,AR subtype distribution varies accordin g to specific spinal cord tract and level. In situ hybridization was perfor med to identify cell bodies containing alpha(1)AR subtype mRNA at four leve ls of human spinal cord (cervical enlargement, thoracic, lumbar, sacral). a lpha(1)AR mRNA is present in ventral gray matter only (ventral > dorsal; sa cral > lumbar = thoracic > cervical). Signaling cell bodies were detected i n anterior horn motor neurons at all levels; dorsal nucleus of Clarke and i ntermediolateral columns in cervical enlargement, thoracic and lumbar spina l cord regions; and parasympathetic nucleus in sacral spinal cord. Although all three alpha(1)AR subtypes are present throughout human spinal cord, al pha(1d) mRNA predominates overall. If confirmed at a protein level, these f indings may contribute to the development of new therapeutic strategies in the treatment of several human diseases. (C) 1999 Elsevier Science B.V. All rights reserved.