Introduction Peptides and Neuropeptides: Definitions Peptides are biologically occurring short chains of amino acid monomers linked by amide bonds. Arbitrarily, peptides are distinguished from proteins on the basis of size: they contain approximately 50 or fewer amino acids. Neuropeptides are…
Introduction This chapter updates the data supporting the hypothesis that adenosine (Ado) is a metabolic regulator of cerebral blood flow (CBF). A metabolic regulator is a substance whose concentration reflects and is linked to cellular metabolism. If a factor is…
Introduction The brain circulation is generally believed to be controlled by (1) chemical factors as perivascular pH; (2) autoregulation, a response to changes in systemic blood pressure; and (3) intrinsic mechanisms within the brain via neurovascular units and the microvasculature.…
Introduction The brain requires oxygen and glucose to meet its metabolic demands, and cerebral blood flow (CBF) is its supply channel. The brain has high energy requirements but limited storage capacity, which means persistent CBF is critical for its proper…
Introduction The effects of carbon dioxide (CO 2 ), oxygen (O 2 ), and nitric oxide (NO) on the cerebrovasculature are the most pronounced, easily demonstrated, and reproduced phenomena observed in the cerebral circulation. Studies in man and animals, using…
Introduction: From Static to Dynamic The human brain constitutes only 2% of the body weight, but receives 15% of cardiac output, accounts for almost 20% of the total oxygen consumption, and consumes approximately 25% of total body glucose utilization. The…
Introduction The blood–brain barrier (BBB) serves to limit the exposure of the brain parenchyma to foreign substances. Early experiments illustrate the “barrier” function present in the neurovasculature, as tracers such as peroxidase injected systemically are confined to vessel lumens or…
Introduction The vascular endothelium is a simple monolayer of cells that line the capillary lumen and is optimally placed at the interface of the blood circulation and vessel wall. Once considered to be merely a “cellophane wrapper” of the vessel…
Acknowledgments Work summarized in this chapter was supported by research grants from the National Institute of Health (HL-62984 and HL-113863), the Department of Veteran’s Affair’s (BX001399), the Fondation Leducq (Transatlantic Network of Excellence), and the National Health and Medical Research…
Introduction Vasa vasorum (VV) are defined literally as vessels of vessels, and are predominantly observed in large vessels with an important role under pathological conditions. Research on noncerebral VV has been established for over a century, including cardiac, pulmonary, aortic,…