Title: QUANTITATIVE CHARACTERIZATION OF BETA-ADRENERGIC-RECEPTOR SUBTYPES IN PORCINE ADIPOCYTES

Author(s): COUTINHO LL , BERGEN WG, MERKEL RA, SMITH CK

Source:  COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY C-PHARMACOLOGY TOXICOLOGY & ENDOCRINOLOGY 101 (3): 481-485 APR 1992

Document Type:  Article

Language:  English

Abstract:  1. Two populations of beta-adrenergic receptor (beta-AR) subtypes and their proportions were characterized in adipocytes isolated from subcutaneous adipose tissue of castrated male crossbred pigs (60-85 kg).

2. Specific binding of the radioligand I-125-iodopindolol (IPIN) to crude plasma membranes (70-90% of total binding) reached equilibrium conditions in 30 min (38-degrees-C), was tissue concentration-dependent, stereospecific and saturable (b(max) = 168 +/- 5.8 fmol/mg protein).

3. Displacement curves by ICI 89,406 were best-fit by a two site model (P < 0.01) that indicated the presence of two receptor populations and selectivity of IPIN for the beta-2AR subtype.

4. Forty-five percent of the receptors had a high affinity for ICI 89,406, K(i) = 2.27 +/- 0.68 nM and were classified as beta-1AR.

KeyWords Plus:  SWINE ADIPOSE-TISSUE; BINDING; RADIOLIGANDS; LIPOLYSIS

Addresses:  ELI LILLY & CO, LILLY RES LABS, POB 708, GREENFIELD, IN 46140 USA
MICHIGAN STATE UNIV, DEPT ANIM SCI, E LANSING, MI 48824 USA

Publisher:  PERGAMON-ELSEVIER SCIENCE LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB

Subject Category:  BIOCHEMISTRY & MOLECULAR BIOLOGY; ENDOCRINOLOGY & METABOLISM; TOXICOLOGY; ZOOLOGY

IDS Number:  HV174

ISSN:  0742-8413