Alpha-adrenergic-induced changes in hamster (Mesocricetus) brown adipocyte respiration and membrane potential

Barbara A Horwitz, J. Hamilton

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

1. Respiratory rates of brown adipocytes were stimulated by 10 μM phenylephrine, the magnitude of this stimulation being about only one-third that evoked by 1 μM isoproterenol, or norepinephrine. 2. The smaller thermogenic response to phenylephrine did not reflect limited substrate availability as shown by the finding that respiration with phenylephrine plus butyrate was not greater than that with phenylephrine or butyrate alone. 3. These data also imply that the thermogenic response to the α-agonist does not involve a significant degree of mitochondrial uncoupling. 4. Examination of in vivo changes in brown adipocyte membrane potentials indicated that phenylephrine and isoproterenol can each elicit multiphasic responses (i.e. depolarization followed by hyperpolarization and a second depolarization), although the magnitude and duration of each phase differed for the two agonists. 5. The initial depolarization occurring within seconds after norepinephrine injection appears to result primarily from activation of α-adrenergic receptors, with a small contribution from the β -pathway. 6. Similarly, the subsequent hyperpolarization and second depolarization primarily reflect events associated with the activated β-adrenergic pathway, with a modest contribution from α-mediated events.

Original languageEnglish (US)
Pages (from-to)99-104
Number of pages6
JournalComparative Biochemistry and Physiology. Part C, Comparative
Volume78
Issue number1
DOIs
StatePublished - 1984

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Brown Adipocytes
Mesocricetus
Phenylephrine
Cricetinae
Adrenergic Agents
Membrane Potentials
Respiration
Butyrates
Isoproterenol
Norepinephrine
Respiratory Rate
Adrenergic Receptors
Injections

ASJC Scopus subject areas

  • Immunology
  • Pharmacology

Cite this

Alpha-adrenergic-induced changes in hamster (Mesocricetus) brown adipocyte respiration and membrane potential. / Horwitz, Barbara A; Hamilton, J.

In: Comparative Biochemistry and Physiology. Part C, Comparative, Vol. 78, No. 1, 1984, p. 99-104.

Research output: Contribution to journalArticle

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