Document Detail

Characterization of perfused periaortic brown adipose tissue from the rat.
MedLine Citation:
PMID:  7922865     Owner:  NLM     Status:  MEDLINE    
A technique was developed for the perfusion of periaortic brown adipose tissue (BAT) with a view to assessing vascular system involvement in BAT thermogenesis. The procedure involved cannulation of the thoracic aorta and ligation of the intercostal branches and the distal thoracic aorta. Perfusion was conducted in a buffer-filled chamber using constant flow at 37 degrees C. Lactate dehydrogenase leakage was less than 2%/h, and after 30 min of perfusion the energy charge was 0.72 +/- 0.05 (n = 4) and differed little from freshly sampled interscapular BAT (0.71 +/- 0.03 (n = 7)). Periaortic BAT was indistinguishable from interscapular BAT in enzyme content, mitochondrial size, mitochondrial cristae, lipid content, and cell size. Basal oxygen consumption (VO2) was 64.3 +/- 7.4 mumol.h-1.g-1 wet weight, and basal perfusion pressure was 65 +/- 3 mmHg (1 mmHg = 133.3 Pa). Norepinephrine and isoproterenol each increased VO2 of perfused periaortic BAT in a time-dependent and reversible manner. Half-maximal stimulation of VO2 occurred at 12 nM norepinephrine and 8 nM isoproterenol; maximally stimulated tissue had a VO2 of approximately 150 mumol.h-1.g-1 wet weight. Norepinephrine (50 nM) had no consistent effect on perfusion pressure, but the increase in VO2 by this agonist was completely blocked by 10 microM DL-propranolol and unaffected by phentolamine (1-20 microM) or nitroprusside (0.01-1 mM). Increasing the perfusion flow rate increased pressure and had no effect on basal VO2 but increased the VO2 response due to norepinephrine.(ABSTRACT TRUNCATED AT 250 WORDS)
A Matthias; S M Richards; K A Dora; M G Clark; E Q Colquhoun
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Publication Detail:
Type:  In Vitro; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Canadian journal of physiology and pharmacology     Volume:  72     ISSN:  0008-4212     ISO Abbreviation:  Can. J. Physiol. Pharmacol.     Publication Date:  1994 Apr 
Date Detail:
Created Date:  1994-11-14     Completed Date:  1994-11-14     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0372712     Medline TA:  Can J Physiol Pharmacol     Country:  CANADA    
Other Details:
Languages:  eng     Pagination:  344-52     Citation Subset:  IM    
Department of Biochemistry, University of Tasmania, Hobart, Australia.
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MeSH Terms
Adipose Tissue, Brown / metabolism,  physiology*,  ultrastructure
Aorta, Thoracic / physiology*,  ultrastructure
Body Temperature Regulation / drug effects
Cell Size
Isoproterenol / pharmacology
L-Lactate Dehydrogenase / metabolism
Lipid Metabolism
Microscopy, Electron
Mitochondria, Muscle / metabolism,  ultrastructure
Norepinephrine / pharmacology
Oxygen Consumption / drug effects,  physiology
Phentolamine / pharmacology
Phosphates / metabolism
Propranolol / pharmacology
Rats, Wistar
Vasoconstriction / drug effects
Vasodilation / drug effects
Reg. No./Substance:
0/Phosphates; 50-60-2/Phentolamine; 51-41-2/Norepinephrine; 525-66-6/Propranolol; 7683-59-2/Isoproterenol; EC Dehydrogenase

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