Enhanced insulin binding to blood-brain barrier in vivo and to brain microvessels in vitro in newborn rabbits

Journal Article · Thu Aug 01 00:00:00 EDT 1985 · Diabetes; (United States)

DOI:https://doi.org/10.2337/diab.34.8.728· OSTI ID:6181111

Frank, H J; Jankovic-Vokes, T; Pardridge, W M; Morris, W L

Insulin is a known growth factor in nonneural tissue, and recent studies have shown that there are insulin receptors throughout the adult and fetal central nervous system. Since insulin has only limited access to the adult brain, this study was undertaken to determine if insulin has increased availability to the newborn brain where it may act as a neonatal brain growth promoter. In vivo brain uptake of SVI-insulin after a single-pass carotid injection was measured in newborn, 3-wk-old and 11-wk-old (adult) rabbits. The brain uptake index (BUI) relative to a THOH reference was 22.0 +/- 1.1% (mean +/- SEM) for newborn, 12.8 +/- 0.6% for 3-wk-old, and 6.5 +/- 0.1% for adults. Specific SVI-insulin binding to isolated cerebral microvessels was similarly increased in the newborn compared with the 3-wk-old and adult animals. Scatchard analysis revealed that the difference was due to an increase in receptor number with only minimal changes in the affinity. The increased availability of circulating insulin to the newborn brain was further corroborated by elevated CSF/serum and brain/serum insulin ratios in the newborn versus adult. These results suggest that insulin has increased access to the newborn brain where it may function as a growth factor.

• OSTI ID: 6181111
• Journal Information: Diabetes; (United States), Vol. 8
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
BLOOD-BRAIN BARRIER
PHYSIOLOGY
INSULIN
UPTAKE
IODINE 125
AGE DEPENDENCE
AGING
ANIMAL GROWTH
BRAIN
CAPILLARIES
IN VITRO
NEONATES
RABBITS
RECEPTORS
TRITIUM OXIDES
ANIMALS
BETA DECAY RADIOISOTOPES
BLOOD VESSELS
BODY
CARDIOVASCULAR SYSTEM
CENTRAL NERVOUS SYSTEM
CHALCOGENIDES
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
GROWTH
HORMONES
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPES
LABELLED COMPOUNDS
MAMMALS
NERVOUS SYSTEM
NUCLEI
ODD-EVEN NUCLEI
ORGANS
OXIDES
OXYGEN COMPOUNDS
PEPTIDE HORMONES
RADIOISOTOPES
TRITIUM COMPOUNDS
VERTEBRATES
550601* - Medicine- Unsealed Radionuclides in Diagnostics