Acute exposure to cold rapidly increases the number of nucleotide binding sites, but not proton conductance, in BAT mitochondria

Conference · Sat Mar 01 04:00:00 EST 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5458208

Swick, A G; Swick, R W

Studies on the effect of acute cold exposure of rats on brown adipose tissue (BAT) thermogenic activity have produced equivocal results. Therefore, the authors have reexamined the response of BAT mitochondria to abrupt changes in environmental temperature. /sup 3/H-GDP binding to BAT mitochondria increased more than 2-fold in 20 min when rats were moved from 27/sup 0/C to 4/sup 0/C. When rats housed at 4/sup 0/C for 2 h were returned to 27/sup 0/C, GDP binding decreased sharply in 20 min and returned to control levels in 2 h. On the other hand, GDP-inhibitable proton conductance, as measured by passive swelling in isotonic K-acetate of KCl buffers, was unaffected by brief cold exposure but more than doubled in rats kept at 4/sup 0/C for 10 days. The authors conclude that GDP-inhibitable swelling may be more indicative of uncoupling protein concentration whereas thermogenic activity is more appropriately indicated by GDP binding. GDP binding to BAT mitochondria from warm and acutely cold treated rats was not altered by prior swelling of the mitochondria nor by freeze-thawing the mitochondria before assay. Therefore, alterations of the number of GDP binding sites may not be a result of conformational changes of the mitochondril membrane.

• Research Organization: Univ. of Wisconsin, Madison
• OSTI ID: 5458208
• Report Number(s): CONF-8604222-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 45:3
• Country of Publication: United States
• Language: English

Related Subjects

550201 -- Biochemistry-- Tracer Techniques
560205* -- Thermal Effects-- Vertebrates-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ACUTE EXPOSURE
ADIPOSE TISSUE
ANIMAL TISSUES
ANIMALS
AROMATICS
AZAARENES
BARYONS
BIOCHEMICAL REACTION KINETICS
BODY
CELL CONSTITUENTS
CONNECTIVE TISSUE
ELEMENTARY PARTICLES
FERMIONS
GUANOSINE
HADRONS
HETEROCYCLIC COMPOUNDS
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
MAMMALS
MEMBRANE PROTEINS
MITOCHONDRIA
NUCLEONS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANOIDS
PROTEINS
PROTONS
PURINES
RATS
REACTION KINETICS
RECEPTORS
RIBOSIDES
RODENTS
TEMPERATURE EFFECTS
TISSUES
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES