The blood-brain barrier: connecting the gut and the brain.
The BBB prevents the unrestricted exchange of substances between the central nervous system (CNS) and the blood. The blood-brain barrier (BBB) also conveys information between the CNS and the gastrointestinal (GI) tract through several mechanisms. Here, we review three of those mechanisms. First, the BBB selectively transports some peptides and regulatory proteins in the blood-to-brain or the brain-to-blood direction. The ability of GI hormones to affect functions of the BBB, as illustrated by the ability of insulin to alter the BBB transport of amino acids and drugs, represents a second mechanism. A third mechanism is the ability of GI hormones to affect the secretion by the BBB of substances that themselves affect feeding and appetite, such as nitric oxide and cytokines. By these and other mechanisms, the BBB regulates communications between the CNS and GI tract.
Banks
William A
WA
GRECC, Veterans Affairs Medical Center-St. Louis and Saint Louis University School of Medicine, Division of Geriatrics, Department of Internal Medicine, WAB, 915 N. Grand Blvd, St. Louis, MO 63106, USA. bankswa@slu.edu
D000818:Animals; D001692:Biological Transport / Q000502:physiology; D001812:Blood-Brain Barrier / Q000378:metabolism* / Q000502:physiology; D001921:Brain / Q000378:metabolism*; D002490:Central Nervous System / Q000378:metabolism*; D041981:Gastrointestinal Tract / Q000378:metabolism*; D054439:Ghrelin / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000378:metabolism; D020738:Leptin / Q000378:metabolism; D008954:Models, Biological; D036361:Peptide Hormones / Q000378:metabolism*
D054439:Ghrelin; D007328:Insulin; D020738:Leptin; D036361:Peptide Hormones