Display Settings:

Format

Send to:

Choose Destination
Endocrinology. 2012 Sep;153(9):4111-9. doi: 10.1210/en.2012-1435. Epub 2012 Jul 9.

Brain meets body: the blood-brain barrier as an endocrine interface.

Author information

  • Veterans Affairs Puget Sound Health Care System and Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA. wabanks1@uw.edu

Abstract

The blood-brain barrier (BBB) separates the central nervous system (CNS) from the peripheral tissues. However, this does not prevent hormones from entering the brain, but shifts the main control of entry to the BBB. In general, steroid hormones cross the BBB by transmembrane diffusion, a nonsaturable process resulting in brain levels that reflect blood levels, whereas thyroid hormones and many peptides and regulatory proteins cross using transporters, a saturable process resulting in brain levels that reflect blood levels and transporter characteristics. Protein binding, brain-to-blood transport, and pharmacokinetics modulate BBB penetration. Some hormones have the opposite effect within the CNS than they do in the periphery, suggesting that these hormones cross the BBB to act as their own counterregulators. The cells making up the BBB are also endocrine like, both responding to circulating substances and secreting substances into the circulation and CNS. By dividing a hormone's receptors into central and peripheral pools, the former of which may not be part of the hormone's negative feed back loop, the BBB fosters the development of variable hormone resistance syndromes, as exemplified by evidence that altered insulin action in the CNS can contribute to Alzheimer's disease. In summary, the BBB acts as a regulatory interface in an endocrine-like, humoral-based communication between the CNS and peripheral tissues.

PMID:
22778219
[PubMed - indexed for MEDLINE]
PMCID:
PMC3423627
Free PMC Article

Images from this publication.See all images (2)Free text

Fig. 1.
Fig. 2.
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Atypon Icon for PubMed Central
    Loading ...
    Write to the Help Desk