Modulation of receptors and adenylate cyclase activity during sucrose feeding, food deprivation, and cold exposure

Journal Article · Tue Dec 01 04:00:00 EST 1987 · American Journal of Physiology; (USA)

OSTI ID:6994913

Scarpace, P J; Baresi, L A; Morley, J E ^[1]

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1. Veterans Administration Medical Center, Los Angeles, CA (USA) Univ. of California, Los Angeles (USA)

Thermogenesis in brown adipose tissue (BAT) serves as a regulator of body temperature and weight maintenance. Thermogenesis can be stimulated by catecholamine activation of adenylate cyclase through the {beta}-adrenergic receptor. To investigate the effects of sucrose feeding, food deprivation, and cold exposure on the {beta}-adrenergic pathway, adenylate cyclase activity and {beta}-adrenergic receptors were assessed in rat BAT after 2 wk of sucrose feeding, 2 days of food deprivation, or 2 days of cold exposure. {beta}-Adrenergic receptors were identified in BAT using ({sup 125}I)iodocyanopindolol. Binding sites had the characteristics of mixed {beta}{sub 1}- and {beta}{sub 2}-type adrenergic receptors at a ratio of 60/40. After sucrose feeding or cold exposure, there was the expected increase in BAT mitochondrial mass as measured by total cytochrome-c oxidase activity but a decrease in {beta}-adrenergic receptor density due to a loss of the {beta}{sub 1}-adrenergic subtype. This BAT {beta}-adrenergic receptor downregulation was tissue specific, since myocardial {beta}-adrenergic receptors were unchanged with either sucrose feeding or cold exposure. Forskolin-stimulated adenylate cyclase activity increased in BAT after sucrose feeding or cold exposure but not after food deprivation. These data suggest that in BAT, sucrose feeding or cold exposure result in downregulation of {beta}-adrenergic receptors and that isoproterenol-stimulated adenylate cyclase activity was limited by receptor availability.

• OSTI ID: 6994913
• Journal Information: American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 253:6; ISSN 0002-9513; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ADIPOSE TISSUE
AMINES
ANIMAL TISSUES
ANIMALS
AROMATICS
AZAARENES
AZOLES
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL PATHWAYS
BODY
CARBOHYDRATES
CATECHOLAMINES
CONNECTIVE TISSUE
CYCLASES
DAYS LIVING RADIOISOTOPES
DIET
DISACCHARIDES
ELECTRON CAPTURE RADIOISOTOPES
ENZYME ACTIVITY
ENZYMES
FASTING
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
INDOLES
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LYASES
MAMMALS
MEMBRANE PROTEINS
NUCLEI
ODD-EVEN NUCLEI
OLIGOSACCHARIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHENOLS
PHYSIOLOGY
POLYPHENOLS
PROTEINS
PYRROLES
RADIOISOTOPES
RADIORECEPTOR ASSAY
RATS
REACTION KINETICS
RECEPTORS
RODENTS
SACCHARIDES
SACCHAROSE
TEMPERATURE DEPENDENCE
TISSUES
TRACER TECHNIQUES
VERTEBRATES
WEIGHT