PMID- 2859355
OWN - NLM
STAT- MEDLINE
DCOM- 19850618
LR  - 20190630
IS  - 0022-3042 (Print)
IS  - 0022-3042 (Linking)
VI  - 44
IP  - 6
DP  - 1985 Jun
TI  - Human blood-brain barrier insulin receptor.
PG  - 1771-8
AB  - A new model system for characterizing the human brain capillary, which makes up 
      the blood-brain barrier (BBB) in vivo, is described in these studies and is 
      applied initially to the investigation of the human BBB insulin receptor. Autopsy 
      brains were obtained from the pathologist between 22-36 h postmortem and were 
      used to isolate human brain microvessels which appeared intact on both light and 
      phase microscopy. The microvessels were positive for human factor 8 and for a 
      BBB-specific enzyme marker, gamma-glutamyl transpeptidase. The microvessels 
      avidly bound insulin with a high-affinity dissociation constant, KD = 1.2 +/- 0.5 
      nM. The human brain microvessels internalized insulin based on acid-wash assay, 
      and 75% of insulin was internalized at 37 degrees C. The microvessels transported 
      insulin to the medium at 37 degrees C with a t1/2 = approximately 70 min. Little 
      of the 125I-insulin was metabolized by the microvessels under these conditions 
      based on the elution profile of the medium extract over a Sephadex G-50 column. 
      Plasma membranes were obtained from the human brain microvessels and these 
      membranes were enriched in membrane markers such as gamma-glutamyl transpeptidase 
      or alkaline phosphatase. The plasma membranes bound 125I-insulin with and ED50 = 
      10 ng/ml, which was identical to the 50% binding point in intact microvessels. 
      The human BBB plasma membranes were solubilized in Triton X-100 and were adsorbed 
      to a wheat germ agglutinin Sepharose affinity column, indicating the BBB insulin 
      receptor is a glycoprotein. Affinity cross-linking of insulin to the plasma 
      membranes revealed a 127K protein that specifically binds insulin.(ABSTRACT 
      TRUNCATED AT 250 WORDS)
FAU - Pardridge, W M
AU  - Pardridge WM
FAU - Eisenberg, J
AU  - Eisenberg J
FAU - Yang, J
AU  - Yang J
LA  - eng
GR  - R01-NS-17701/NS/NINDS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - England
TA  - J Neurochem
JT  - Journal of neurochemistry
JID - 2985190R
RN  - 0 (Insulin)
RN  - EC 2.3.2.2 (gamma-Glutamyltransferase)
RN  - EC 2.7.10.1 (Receptor, Insulin)
SB  - IM
MH  - Aged
MH  - *Blood-Brain Barrier
MH  - Cell Membrane/metabolism
MH  - Endocytosis
MH  - Exocytosis
MH  - Female
MH  - Humans
MH  - In Vitro Techniques
MH  - Insulin/metabolism
MH  - Male
MH  - Microcirculation/metabolism
MH  - Middle Aged
MH  - Receptor, Insulin/*analysis
MH  - gamma-Glutamyltransferase/analysis
EDAT- 1985/06/01 00:00
MHDA- 1985/06/01 00:01
CRDT- 1985/06/01 00:00
PHST- 1985/06/01 00:00 [pubmed]
PHST- 1985/06/01 00:01 [medline]
PHST- 1985/06/01 00:00 [entrez]
AID - 10.1111/j.1471-4159.1985.tb07167.x [doi]
PST - ppublish
SO  - J Neurochem. 1985 Jun;44(6):1771-8. doi: 10.1111/j.1471-4159.1985.tb07167.x.