Tissue functions mediated by beta(3)-adrenoceptors-findings and challenges.

Archiv für Experimentelle Pathologie und Pharmakologie (Impact Factor: 2.15). 08/2010; 382(2):103-8. DOI: 10.1007/s00210-010-0529-2
Source: PubMed

ABSTRACT As β3-adrenoceptor agonists metamorphose from experimental tools into therapeutic drugs, it is vital to obtain a comprehensive
picture of the cell and tissue functions mediated by this receptor subtype in humans. Human tissues with proven functions
and/or a high expression of β3-adrenoceptors include the urinary bladder, the gall bladder, and other parts of the gastrointestinal tract. While several
other β3-adrenoceptor functions have been proposed based on results obtained in animals, their relevance to humans remains uncertain.
For instance, β3-adrenoceptors perform an important role in thermogenesis and lipolysis in rodent brown and white adipose tissue, respectively,
but their role in humans appears less significant. Moreover, the use of tools such as the agonist BRL 37344 and the antagonist
SR59230A to demonstrate functional involvement of β3-adrenoceptors may lead in many cases to misleading conclusions as they can also interact with other β-adrenoceptor subtypes
or even non-adrenoceptor targets. In conclusion, we propose that many responses attributed to β3-adrenoceptor stimulation may need re-evaluation in the light of the development of more selective tools. Moreover, findings
in experimental animals need to be extended to humans in order to better understand the potential additional indications and
side effects of the β3-adrenoceptor agonists that are beginning to enter clinical medicine.

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