Cultured bovine brain capillary endothelial cells (BBCEC) - a blood-brain barrier model for studying the binding and internalization of insulin and insulin-like growth factor 1

Conference · Fri May 01 00:00:00 EDT 1987 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:6278896

Keller, B T; Borchardt, R T

Cultured bovine brain capillary endothelial cells (BBCEC) have previously been reported by their laboratory as a working model for studying nutrient and drug transport and metabolism at the blood-brain barrier. In the present study, they have utilized this culture system to investigate the binding and internalization of (/sup 125/I)-labelled insulin (INS) and insulin-like growth factor 1(IGF-1) by BBCEC. After 2 hrs at 23/sup 0/C, the specific binding of INS and IGF-1 was 1.6% and 13.6%, respectively. At 37/sup 0/C, the maximum specific binding was 0.9% for INS and 5.8% for IGF-1. Using an acid-wash technique to assess peptide internalization, it was observed that, at 37/sup 0/C, approximately 60% of the bound INS rapidly became resistant to acid treatment, a value which was constant over 2 hr. With IGF-1, a similar proportion of the bound material, 62%, became resistant by 30 min, but subsequently decreased to 45% by 2 hr. Scatchard analysis of competitive binding studies indicated the presence of two binding sites for each protein, having K/sub d/'s of 0.82 nM and 19.2 nM for INS and 0.39 nM and 3.66 nM for IGF-1. Little change in the amount of INS binding was observed over a four-day interval as the cultures became a confluent monolayer. The present report of binding and internalization of these proteins suggests that the BBCEC may utilize a receptor-mediated process to internalize and/or transport (transcytosis) INS and IGF-1 from the circulation.

• Research Organization: Univ. of Kansas, Lawrence
• OSTI ID: 6278896
• Report Number(s): CONF-870644-
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 46:6; Conference: 78. annual meeting of the American Society of Biological Chemists conference, Philadelphia, PA, USA, 7 Jun 1987
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
BLOOD-BRAIN BARRIER
BIOLOGICAL MODELS
INSULIN
BIOCHEMICAL REACTION KINETICS
RECEPTORS
PEPTIDE HORMONES
BRAIN
CAPILLARIES
CATTLE
CELL CULTURES
ENDOTHELIUM
IODINE 125
MEMBRANE TRANSPORT
TRACER TECHNIQUES
ANIMAL TISSUES
ANIMALS
BETA DECAY RADIOISOTOPES
BLOOD VESSELS
BODY
CARDIOVASCULAR SYSTEM
CENTRAL NERVOUS SYSTEM
DAYS LIVING RADIOISOTOPES
DOMESTIC ANIMALS
ELECTRON CAPTURE RADIOISOTOPES
HORMONES
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MAMMALS
MEMBRANE PROTEINS
NERVOUS SYSTEM
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PROTEINS
RADIOISOTOPES
REACTION KINETICS
RUMINANTS
TISSUES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques