Evidence from in vitro differentiating cells that adrenoceptor agonists can increase uncoupling protein mRNA level in adipocytes of adult humans: an RT-PCR study.

In vivo data have suggested that adrenergic signals can reactivate dormant brown adipocytes in adult humans. We report here a system based on primary cultures of perirenal adipocytes from human adults and reverse transcription-PCR of uncoupling protein mRNA. Norepinephrine and compounds classified as beta 3-adrenoceptor agonists in rodents increased uncoupling protein mRNA level in human adipocytes (presumably brown adipocytes). Although we did not demonstrate that the observed effect was mediated by beta 3-adrenoceptors, it is proposed that this system could be used to appreciate the ability of beta-adrenoceptor agonists to activate UCP gene transcription and help to select beta 3-adrenoceptor agonists and antagonists prior to in vivo trials; indeed, the difficulty in developing such drugs that are effective in humans may result from the fact that the screening of molecules has historically been made in rodents.