Metallothionein is expressed in adipocytes of brown fat and is induced by catecholamines and zinc

John H. Beattie, Anne M. Wood, Paul Trayhurn, Bharat Jasani, Adele Vincent, Graeme McCormack, Adrian K. West

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Abstract

Metallothionein (MT) is thought to have an antioxidant function and is strongly expressed during activation of thermogenesis and increased oxidative stress in brown adipose tissue (BAT). Localization and regulation of MT expression in BAT was therefore investigated in rats and mice. Immunohistochemical analysis of BAT from rats exposed to 4°C for 24 h showed that MT and uncoupling protein 1 (UCP1) were coexpressed in differentiated adipocytes, and both cytoplasmic and nuclear localization of MT was observed. Cold induction of MT-1 expression in BAT was also observed in mice. Administration of norepinephrine to rats and isoproterenol to mice stimulated MT and UCP1 expression in BAT, implying a sympathetically mediated pathway for MT induction. In mice, zinc, and particularly dexamethasone, induced MT-2 expression in BAT and liver. Surprisingly, zinc also induced UCP1 in BAT, suggesting that elevated zinc may induce thermogenesis. We conclude that expression of MT in mature brown adipocytes upon β-adrenoceptor activation is consistent with a role in protecting against physiological oxidative stress or in facilitating the mobilization or utilization of energy reserves.

Original languageEnglish
Pages (from-to)R1082-R1089
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Volume278
Issue number4 47-4
Publication statusPublished - Apr 1 2000

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Keywords

  • Cold exposure
  • Dexamethasone
  • Oxidative stress
  • Thermogenesis
  • Uncoupling protein 1

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

Cite this

Beattie, J. H., Wood, A. M., Trayhurn, P., Jasani, B., Vincent, A., McCormack, G., & West, A. K. (2000). Metallothionein is expressed in adipocytes of brown fat and is induced by catecholamines and zinc. American Journal of Physiology - Regulatory Integrative and Comparative Physiology, 278(4 47-4), R1082-R1089.