Radioisotopic method for the measurement of lipolysis in small samples of human adipose tissue

Journal Article · Sun Jan 01 04:00:00 EST 1984 · J. Lipid Res.; (United States)

OSTI ID:7192076

Leibel, R L; Hirsch, J; Berry, E M; Gruen, R K

To facilitate the study of adrenoreceptor response in small needle biopsy samples of human subcutaneous adipose tissue, we developed a dual radioisotopic technique for measuring lipolysis rate. Aliquots (20-75 mg) of adipose tissue fragments were incubated in a buffered albumin medium containing (/sup 3/H)palmitate and (/sup 14/C)glucose, each of high specific activity. In neutral glycerides synthesized in this system, (/sup 14/C)glucose is incorporated exclusively into the glyceride-glycerol moiety and /sup 3/H appears solely in the esterified fatty acid. Alpha-2 and beta-1 adrenoreceptor activation of tissue incubated in this system does not alter rates of /sup 14/C-labeled glyceride accumulation, but does produce a respective increase or decrease in the specific activity of fatty acids esterified into newly synthesized glycerides. This alteration in esterified fatty acid specific activity is reflected in the ratio of /sup 14/C:/sup 3/H in newly synthesized triglycerides extracted from the incubated adipose tissue. There is a high correlation (r . 0.90) between the /sup 14/C:/sup 3/H ratio in triglycerides and the rate of lipolysis as reflected in glycerol release into the incubation medium. The degree of adrenoreceptor activation by various concentrations of lipolytic and anti-lipolytic substances can be assessed by comparing this ratio in stimulated tissue to that characterizing unstimulated tissue or the incubation medium. This technique permits the study of very small, unweighed tissue biopsy fragments, the only limitation on sensitivity being the specific activity of the medium glucose and palmitate. It is, therefore, useful for serial examinations of adipose tissue adrenoreceptor dose-response characteristics under a variety of clinical circumstances.

• Research Organization: Laboratory of Human Behavior and Metabolism, Rockefeller University, New York, NY
• OSTI ID: 7192076
• Journal Information: J. Lipid Res.; (United States), Journal Name: J. Lipid Res.; (United States) Vol. 25:1; ISSN JLPRA
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
ADIPOSE TISSUE
ADRENAL HORMONES
ALDEHYDES
ANIMAL TISSUES
BODY
CARBOHYDRATES
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
CONNECTIVE TISSUE
DUAL-ISOTOPE SUBTRACTION TECHNIQUE
GLUCOSE
HEXADECANOIC ACID
HEXOSES
HORMONES
ISOTOPE APPLICATIONS
ISOTOPE RATIO
LABELLED COMPOUNDS
LIPIDS
METABOLISM
MONOCARBOXYLIC ACIDS
MONOSACCHARIDES
ORGANIC ACIDS
ORGANIC COMPOUNDS
RECEPTORS
SACCHARIDES
STEROID HORMONES
TISSUES
TRACER TECHNIQUES
TRITIUM COMPOUNDS