Insulin binding to brain capillaries is reduced in genetically obese, hyperinsulinemic Zucker rats

Journal Article · Tue May 01 00:00:00 EDT 1990 · Peptides (Fayetteville, New York); (USA)

DOI:https://doi.org/10.1016/0196-9781(90)90044-6· OSTI ID:6529799

Schwartz, M W; Figlewicz, D F; Kahn, S E; Baskin, D G; Greenwood, M R; Porte, D Jr ^[1]

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1. Univ. of Washington, Seattle (USA)

In order to study the role of plasma insulin in regulating the binding of insulin to the endothelium of the blood-brain barrier (BBB), insulin binding to a purified preparation of brain capillaries was measured in both genetically obese Zucker rats and lean Zucker controls. We found a reduction of 65% in brain capillary insulin binding site number in the obese compared to lean rats with no change in receptor affinity. Furthermore, specific insulin binding to brain capillaries was negatively correlated (p less than 0.05) to the plasma insulin level, suggesting a role for plasma insulin in regulating insulin binding. A similar relationship was observed between insulin receptor number in liver membranes and the plasma insulin level. We conclude that obese, hyperinsulinemic Zucker rats exhibit a reduction in the number of BBB insulin receptors, which parallels the reduction seen in other peripheral tissues. Since insulin receptors have been hypothesized to participate in the transport of insulin across the BBB, the reduction observed in the obese rats may account for the decrease in cerebrospinal fluid insulin uptake previously demonstrated in these animals.

• OSTI ID: 6529799
• Journal Information: Peptides (Fayetteville, New York); (USA), Journal Name: Peptides (Fayetteville, New York); (USA) Vol. 11:3; ISSN PPTDD; ISSN 0196-9781
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ADIPOSE TISSUE
ALDEHYDES
ANIMAL TISSUES
ANIMALS
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL MATERIALS
BLOOD VESSELS
BLOOD-BRAIN BARRIER
BODY
BODY FLUIDS
BRAIN
CAPILLARIES
CARBOHYDRATES
CARDIOVASCULAR SYSTEM
CENTRAL NERVOUS SYSTEM
CEREBROSPINAL FLUID
CONNECTIVE TISSUE
ENDOTHELIUM
GLUCOSE
HEXOSES
HORMONES
INSULIN
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MAMMALS
MATERIALS
MEMBRANE PROTEINS
MEMBRANE TRANSPORT
MONOSACCHARIDES
NERVOUS SYSTEM
ORGANIC COMPOUNDS
ORGANS
PEPTIDE HORMONES
PROTEINS
RATS
REACTION KINETICS
RECEPTORS
RODENTS
SACCHARIDES
TISSUES
TRACER TECHNIQUES
VERTEBRATES