Differential expression of two alpha 2-adrenergic receptor subtype mRNAs in human tissues.
BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1992;
16:57-63. [PMID:
1334200 DOI:
10.1016/0169-328x(92)90193-f]
[Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Genetic subtypes of alpha 2-adrenergic receptors (AR) may mediate distinct physiological functions, and undergo differential cell type-specific regulation. Thus, these distinct receptor subtypes are possible targets for the development of subtype-selective drugs. We have analyzed the tissue distribution of two human alpha 2-adrenoceptor subtype gene mRNAs, alpha 2-C4 and alpha 2-C10, in normal human fetal and adult tissues. Both receptor subtype mRNAs were abundantly expressed in fetal brain and choroid plexus. In non-neural fetal tissues, alpha 2-C10 mRNA was detected in spleen, kidney, adrenal gland, and skin, while alpha 2-C4 transcripts were observed only in kidney and skin. Most regions of the adult brain also expressed both subtypes, but with marked quantitative differences. For example, cerebral cortex contained predominantly alpha 2-C10 mRNA, whereas the caudate nucleus expressed mostly alpha 2-C4 mRNA. In adult peripheral tissues, alpha 2-C10 mRNA expression was most abundant in spleen and renal cortex, and expression of alpha 2-C4 mRNA was strongest in renal cortex and medulla. These different expression patterns provide evidence for the differential regulation of the two alpha 2-adrenergic receptor genes and warrant further investigation with techniques capable of improved anatomical resolution. Regional differences in receptor subtype expression may be valuable for the development of new, subtype-selective pharmacological agents with more targeted actions compared to currently used alpha 2-adrenoceptor agonists and antagonists.
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