Abstract
1. The (Na+/K+-ATPase activity of brown fat membranes is increased by norepinephrine, the physiological mediator of thermogenesis in this tissue. 2. This increased ATPase activity was inhibited approximately 50% by either propranolol (a β-adrenergic blocker) or phentolamine (an α-blocker). 3. The α-agonist, phenylephrine and the β-agonist, isoproterenol, also stimulated the ATPase activity. 4. That these latter effects were receptor-specific is supported by the finding that: (a) l(-)isoproterenol stimulation was inhibited by propranolol but not by phentolamine; (b) d(+)isoproterenol had no stimulatory effect on the ATPase activity; and (c) the l(-)phenylephrine-induced increase was inhibited by phentolamine but not by propranolol. 5. (-)norepinephrine, l(-)isoproterenol and l(-)phenylephrine all decreased the apparent Km for K+ of the (Na+/K+-ATPase but did not alter the apparent Kmfor ATP or the Vmax of the reaction.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 355-360 |
| Number of pages | 6 |
| Journal | Comparative Biochemistry and Physiology. Part C, Comparative |
| Volume | 74 |
| Issue number | 2 |
| DOIs | |
| State | Published - 1983 |
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ASJC Scopus subject areas
- Immunology
- Pharmacology
Cite this
Kinetic characteristics of hamster (mesocricetus auratus) brown fat (Na+/K+)-ATPase : Effects of catecholamines. / Hettinger, D. R.; Horwitz, Barbara A.
In: Comparative Biochemistry and Physiology. Part C, Comparative, Vol. 74, No. 2, 1983, p. 355-360.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Kinetic characteristics of hamster (mesocricetus auratus) brown fat (Na+/K+)-ATPase
T2 - Effects of catecholamines
AU - Hettinger, D. R.
AU - Horwitz, Barbara A
PY - 1983
Y1 - 1983
N2 - 1. The (Na+/K+-ATPase activity of brown fat membranes is increased by norepinephrine, the physiological mediator of thermogenesis in this tissue. 2. This increased ATPase activity was inhibited approximately 50% by either propranolol (a β-adrenergic blocker) or phentolamine (an α-blocker). 3. The α-agonist, phenylephrine and the β-agonist, isoproterenol, also stimulated the ATPase activity. 4. That these latter effects were receptor-specific is supported by the finding that: (a) l(-)isoproterenol stimulation was inhibited by propranolol but not by phentolamine; (b) d(+)isoproterenol had no stimulatory effect on the ATPase activity; and (c) the l(-)phenylephrine-induced increase was inhibited by phentolamine but not by propranolol. 5. (-)norepinephrine, l(-)isoproterenol and l(-)phenylephrine all decreased the apparent Km for K+ of the (Na+/K+-ATPase but did not alter the apparent Kmfor ATP or the Vmax of the reaction.
AB - 1. The (Na+/K+-ATPase activity of brown fat membranes is increased by norepinephrine, the physiological mediator of thermogenesis in this tissue. 2. This increased ATPase activity was inhibited approximately 50% by either propranolol (a β-adrenergic blocker) or phentolamine (an α-blocker). 3. The α-agonist, phenylephrine and the β-agonist, isoproterenol, also stimulated the ATPase activity. 4. That these latter effects were receptor-specific is supported by the finding that: (a) l(-)isoproterenol stimulation was inhibited by propranolol but not by phentolamine; (b) d(+)isoproterenol had no stimulatory effect on the ATPase activity; and (c) the l(-)phenylephrine-induced increase was inhibited by phentolamine but not by propranolol. 5. (-)norepinephrine, l(-)isoproterenol and l(-)phenylephrine all decreased the apparent Km for K+ of the (Na+/K+-ATPase but did not alter the apparent Kmfor ATP or the Vmax of the reaction.
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UR - http://www.scopus.com/inward/citedby.url?scp=0020589870&partnerID=8YFLogxK
U2 - 10.1016/0742-8413(83)90114-7
DO - 10.1016/0742-8413(83)90114-7
M3 - Article
C2 - 6133689
AN - SCOPUS:0020589870
VL - 74
SP - 355
EP - 360
JO - Comparative biochemistry and physiology. C: Comparative pharmacology
JF - Comparative biochemistry and physiology. C: Comparative pharmacology
SN - 0742-8413
IS - 2
ER -