Abstract
The present study examines the effects of α- and β-adrenergic antagonists (phentolamine and propranolol, respectively) and agonists (phenylephrine, isoproterenol) on the neurally induced temperature changes and membrane potentials of interscapular brown adipocytes. These studies, performed in vivo with anesthetized rats, indicate that both α- and β-adrenergic components are associated with the biphasic temperature changes observed following sympathetic activation of the tissue. Specifically, the initial transient temperature decrease seen after brown fat stimulation appeared to reflect vasoconstriction mediated primarily via α-receptors, while the subsequent rise in tissue temperature was associated primarily (though perhaps not entirely) with β-adrenergic pathways. In contrast, the redistribution of ions across the membrane of the brown adipocyte, a phenomenon manifested as a membrane depolarization, was elicited by phenylephrine (an α-agonist) as well as by isoproterenol (a β-agonist), with the magnitude of the isoproterenol-induced depolarization being comparable to that of the phenylephrine-induced effect.
| Original language | English (US) |
|---|---|
| Title of host publication | American Journal of Physiology |
| Volume | 232 |
| Edition | 2 |
| State | Published - 1977 |
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ASJC Scopus subject areas
- Medicine(all)
Cite this
Coupling of signals to brown fat : α and β adrenergic responses in intact rats. / Flaim, K. E.; Horwitz, Barbara A; Horowitz, J. M.
American Journal of Physiology. Vol. 232 2. ed. 1977.Research output: Chapter in Book/Report/Conference proceeding › Chapter
}
TY - CHAP
T1 - Coupling of signals to brown fat
T2 - α and β adrenergic responses in intact rats
AU - Flaim, K. E.
AU - Horwitz, Barbara A
AU - Horowitz, J. M.
PY - 1977
Y1 - 1977
N2 - The present study examines the effects of α- and β-adrenergic antagonists (phentolamine and propranolol, respectively) and agonists (phenylephrine, isoproterenol) on the neurally induced temperature changes and membrane potentials of interscapular brown adipocytes. These studies, performed in vivo with anesthetized rats, indicate that both α- and β-adrenergic components are associated with the biphasic temperature changes observed following sympathetic activation of the tissue. Specifically, the initial transient temperature decrease seen after brown fat stimulation appeared to reflect vasoconstriction mediated primarily via α-receptors, while the subsequent rise in tissue temperature was associated primarily (though perhaps not entirely) with β-adrenergic pathways. In contrast, the redistribution of ions across the membrane of the brown adipocyte, a phenomenon manifested as a membrane depolarization, was elicited by phenylephrine (an α-agonist) as well as by isoproterenol (a β-agonist), with the magnitude of the isoproterenol-induced depolarization being comparable to that of the phenylephrine-induced effect.
AB - The present study examines the effects of α- and β-adrenergic antagonists (phentolamine and propranolol, respectively) and agonists (phenylephrine, isoproterenol) on the neurally induced temperature changes and membrane potentials of interscapular brown adipocytes. These studies, performed in vivo with anesthetized rats, indicate that both α- and β-adrenergic components are associated with the biphasic temperature changes observed following sympathetic activation of the tissue. Specifically, the initial transient temperature decrease seen after brown fat stimulation appeared to reflect vasoconstriction mediated primarily via α-receptors, while the subsequent rise in tissue temperature was associated primarily (though perhaps not entirely) with β-adrenergic pathways. In contrast, the redistribution of ions across the membrane of the brown adipocyte, a phenomenon manifested as a membrane depolarization, was elicited by phenylephrine (an α-agonist) as well as by isoproterenol (a β-agonist), with the magnitude of the isoproterenol-induced depolarization being comparable to that of the phenylephrine-induced effect.
UR - http://www.scopus.com/inward/record.url?scp=0017359803&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0017359803&partnerID=8YFLogxK
M3 - Chapter
C2 - 842692
AN - SCOPUS:0017359803
VL - 232
BT - American Journal of Physiology
ER -