Cited by 183Cerebrospinal fluid and hydrocephalusBarrier Structure and Function StudiesIon Transport and Channel Regulation

Evidence for entry of plasma insulin into cerebrospinal fluid through an intermediate compartment in dogs. Quantitative aspects and implications for transport.

Open access
Schwartz, M W, Bergman, R N, Kahn, S E, Taborsky, G J, Fisher, L D, Sipols, A J, Woods, S C, Steil, G M +1 more·1991·Journal of Clinical Investigation

Abstract

To study the route by which plasma insulin enters cerebrospinal fluid (CSF), the kinetics of uptake from plasma into cisternal CSF of both insulin and [14C]inulin were analyzed during intravenous infusion in anesthetized dogs. Four different mathematical models were used: three based on a two-compartment system (transport directly across the blood-CSF barrier by nonsaturable, saturable, or a combination of both mechanisms) and a fourth based on three compartments (uptake via an intermediate compartment). The kinetics of CSF uptake of [14C]inulin infused according to an "impulse" protocol were accurately accounted for only by the nonsaturable two-compartment model (determination coefficient [R2] = 0.879 +/- 0.044; mean +/- SEM; n = 5), consistent with uptake via diffusion across the blood-CSF barrier. When the same infusion protocol and model were used to analyze the kinetics of insulin uptake, the data fit (R2 = 0.671 +/- 0.037; n = 10) was significantly worse than that obtained with [14C]inulin (P = 0.02). Addition of a saturable component of uptake to the two-compartment model improved this fit, but was clearly inadequate for a subset of insulin infusion studies. In contrast, the three-compartment model accurately accounted for CSF insulin uptake in each study, regardless of infusion protocol (impulse infusion R2 = 0.947 +/- 0.026; n = 10; P less than 0.0001 vs. each two-compartment model; sustained infusion R2 = 0.981 +/- 0.003; n = 5). Thus, a model in which insulin passes through an intermediate compartment en route from plasma to CSF, as a part of a specialized transport system for the delivery of insulin to the brain, best accounts for the dynamics of this uptake process. This intermediate compartment could reside within the blood-CSF barrier or it may represent brain interstitial fluid, if CNS insulin uptake occurs preferentially across the blood-brain barrier.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1172/jci115431

Cites

29 of 29 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Insulin concentration dynamics in the blood and in the CSF are characteristic of a two- or three-compartmental model, and are consistent with results reported by Schwartz and coworkers.

    “The simulation results demonstrated that insulin concentration dynamics in the blood and that in the CSF are characteristic of two- or three-compartmental model, and are consistent with the results reported by Schwartz and coworkers [40], where dynamics of CSF insulin was described by a three-compartment model.”

    From A mathematical model of brain glucose homeostasis (2009) · cites this paper as [40]

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

Research works printed but not linked: 1

  1. Woods, S. C., D. P. Figlewicz Lattemann, A. J. Sipols, and D. Porte, Jr. 1988. Baboons as a model for research on metabolism, feeding and the regulation of body weight. In Monographs in Primatology, Vol. 12: Nonhuman Primate Studies and Diabetes, Carbohydrate Intolerance, and Obesity.

Cited by

Sorted by citations

Authors
Schwartz, M. W., Bergman, R. N., Kahn, S. E., Taborsky, G. J., Fisher, L. D., Sipols, A. J., Woods, S. C., Steil, G. M., & Porte, D.
Affiliations
  • University of Washington (US)
  • University of Southern California (US)
  • United States Department of Veterans Affairs (US)
Venue
Journal of Clinical Investigation
Published
1991-10-01
Volume
88
Issue
4
Pages
1272-1281
ISSN
0021-9738 (ISSN-L)
OpenAlex
W1967708672
Cited by
183
References
27
Citations by year
2026: 1 · 2025: 1 · 2024: 4 · 2023: 6 · 2022: 6 · 2021: 7 · 2020: 7 · 2019: 6 · 2018: 8 · 2017: 5 · 2016: 4 · 2015: 5 · 2014: 3 · 2013: 6 · 2012: 5
FWCI
1.57
Type
journal article
Language
en
Open access
Locations
  • Journal of Clinical Investigation (publishedVersion)
  • Europe PMC (PubMed Central) (publishedVersion)
  • PubMed (publishedVersion)
Funders
  • U.S. Department of Veterans Affairs
  • National Institutes of Health (1f32dk008025-01, 2r01dk012829-36)
  • National Institute of Diabetes and Digestive and Kidney Diseases (DK 12829, DK-17047, DK-08025, P30DK017047)
Topics
  • Life Sciences › Neuroscience › Cellular and Molecular Neuroscience › Cerebrospinal fluid and hydrocephalus
  • Life Sciences › Neuroscience › Neurology › Barrier Structure and Function Studies
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Ion Transport and Channel Regulation
Keywords
insulin, cerebrospinal fluid, blood-CSF barrier, intermediate compartment, inulin, two-compartment model, three-compartment model, saturable transport, blood-brain barrier
MeSH terms
Animals, Biological Transport, Blood-Brain Barrier, Dogs, Infusions, Intravenous, Insulin, Inulin, Male, Models, Biological

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review