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Li W, Zou J, Shang J, Gao C, Sun R, Liu R, Cao H, Wang Y, Zhang J. Both the Complexity of Tight Junctions and Endothelial Transcytosis Are Increased During BBB Postnatal Development in Rats. Front Neurosci 2022; 16:850857. [PMID: 35573303 PMCID: PMC9095945 DOI: 10.3389/fnins.2022.850857] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 03/14/2022] [Indexed: 12/01/2022] Open
Abstract
The blood-brain barrier (BBB) comprises a single layer of endothelial cells and maintains a safe and homeostatic environment for proper neuronal function and synaptic transmission. BBB is not a discrete physical barrier, but a complex, dynamic, and adaptable interface. BBB continues to mature under the influence of the neural environment within a short period of time after birth. However, the basic mechanism of BBB formation and maintenance remains a mystery. Early studies have identified two structural characteristics of microvascular endothelium: special tight junctions (TJs) and a very low transcellular vesicle transport rate. Previous studies believed that BBB damage was mainly due to the destruction of tight junctions, and the role of vesicle transcytosis was neglected, so there was a lack of research on its impact on blood-brain barrier. It is urgent to get a better clarification of the unique structural and functional characteristics of the BBB endothelium to explain the role of BBB injury in neurological diseases. RNA sequencing was used to study the molecular characterization of cerebral cortex vascular endothelium by isolating them from neonatal, adolescent and adult rats. For investigation the maintenance mechanism of the BBB, we focused on the cellular and molecular regulation of barrier formation and the two characteristics of microvascular endothelial cells. Interestingly, we found that during the development of the blood-brain barrier, although the tight junctions gradually mature, endothelial cell transcytosis is gradually enhanced, resulting in an increase in the permeability of the blood-brain barrier. This study suggested that under physiological conditions, low vesicle transport is playing an important role in maintaining the integrity of the blood-brain barrier. This study not only summarized the unique characteristics of microvascular endothelial cells, but also illustrated a clarified mechanism of the development and maintenance of BBB which can provide new therapeutic opportunities for central nervous system drug delivery. Raw data of RNA sequencing were deposited in NCBI Sequence Read Archive database (PRJNA790676).
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Affiliation(s)
- Wei Li
- Department of Neurology, Zhengzhou University People’s Hospital, Henan Provincial People’s Hospital, Zhengzhou, China
| | - Jinlong Zou
- Department of Neurology, Henan University People’s Hospital, Henan Provincial People’s Hospital, Zhengzhou, China
| | - Junkui Shang
- Department of Neurology, Zhengzhou University People’s Hospital, Henan Provincial People’s Hospital, Zhengzhou, China
| | - Chenhao Gao
- Department of Neurology, Zhengzhou University People’s Hospital, Henan Provincial People’s Hospital, Zhengzhou, China
| | - Ruihua Sun
- Department of Neurology, Zhengzhou University People’s Hospital, Henan Provincial People’s Hospital, Zhengzhou, China
| | - Ruijie Liu
- Department of Neurology, Henan University People’s Hospital, Henan Provincial People’s Hospital, Zhengzhou, China
| | - Huixia Cao
- Department of Nephrology, Henan Provincial Key Laboratory of Kidney Disease and Immunology, Henan Provincial People’s Hospital, Zhengzhou University People’s Hospital, Henan University People’s Hospital, Zhengzhou, China
| | - Yanliang Wang
- Department of Nephrology, Henan Provincial Key Laboratory of Kidney Disease and Immunology, Henan Provincial People’s Hospital, Zhengzhou University People’s Hospital, Henan University People’s Hospital, Zhengzhou, China
| | - Jiewen Zhang
- Department of Neurology, Zhengzhou University People’s Hospital, Henan Provincial People’s Hospital, Zhengzhou, China
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Blood-brain barrier transport kinetics of the cyclic depsipeptide mycotoxins beauvericin and enniatins. Toxicol Lett 2016; 258:175-184. [DOI: 10.1016/j.toxlet.2016.06.1741] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 06/22/2016] [Accepted: 06/24/2016] [Indexed: 11/20/2022]
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3
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Verbeken M, Wynendaele E, Mauchauffée E, Bracke N, Stalmans S, Bojnik E, Benyhe S, Peremans K, Polis I, Burvenich C, Gjedde A, Hernandez JF, De Spiegeleer B. Blood-brain transfer and antinociception of linear and cyclic N-methyl-guanidine and thiourea-enkephalins. Peptides 2015; 63:10-21. [PMID: 25451468 DOI: 10.1016/j.peptides.2014.10.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 10/20/2014] [Accepted: 10/20/2014] [Indexed: 01/09/2023]
Abstract
Enkephalins are active in regulation of nociception in the body and are key in development of new synthetic peptide analogs that target centrally located opioid receptors. In this study, we investigated the in vivo blood-brain barrier (BBB) penetration behavior and antinociceptive activity of two cyclic enkephalin analogs with a thiourea (CycS) or a N-methyl-guanidine bridge (CycNMe), and their linear counterparts (LinS and LinNMe) in mice, as well as their in vitro metabolic stability. (125)I-LinS had the highest blood-brain clearance (K1=3.46μL/gmin), followed by (125)I-LinNMe, (125)I-CycNMe, and (125)I-CycS (K1=1.64, 0.31, and 0.11μL/gmin, respectively). Also, these peptides had a high metabolic stability (t1/2>1h) in mouse serum and brain homogenate, and half-inhibition constant (Ki) values in the nanomolar range with predominantly μ-opioid receptor selectivity. The positively charged NMe-enkephalins showed a higher antinociceptive activity (LinNMe: 298% and CycNMe: 205%), expressed as molar-dose normalized area under the curve (AUC) relative to morphine, than the neutral S-enkephalins (CycS: 122% and LinS: 130%).
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Affiliation(s)
- Mathieu Verbeken
- Drug Quality and Registration (DruQuaR) group, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, B-9000 Ghent, Belgium
| | - Evelien Wynendaele
- Drug Quality and Registration (DruQuaR) group, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, B-9000 Ghent, Belgium
| | - Elodie Mauchauffée
- Institut des Biomolécules Max Mousseron, UMR5247 CNRS, Universités Montpellier 1 and 2, Faculty of Pharmaceutical Sciences, 15 Avenue Charles Flahault, F-34093 Montpellier, France
| | - Nathalie Bracke
- Drug Quality and Registration (DruQuaR) group, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, B-9000 Ghent, Belgium
| | - Sofie Stalmans
- Drug Quality and Registration (DruQuaR) group, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, B-9000 Ghent, Belgium
| | - Engin Bojnik
- Biological Research Center, Institute of Biochemistry, POB 521, H-6702 Szeged, Hungary
| | - Sandor Benyhe
- Biological Research Center, Institute of Biochemistry, POB 521, H-6702 Szeged, Hungary
| | - Kathelijne Peremans
- Departments of Veterinary Medical Imaging and Small Animal Orthopaedics, Medicine and Clinical Biology of Small Animals and Comparative Physiology and Biometrics, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
| | - Ingeborgh Polis
- Departments of Veterinary Medical Imaging and Small Animal Orthopaedics, Medicine and Clinical Biology of Small Animals and Comparative Physiology and Biometrics, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
| | - Christian Burvenich
- Departments of Veterinary Medical Imaging and Small Animal Orthopaedics, Medicine and Clinical Biology of Small Animals and Comparative Physiology and Biometrics, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
| | - Albert Gjedde
- Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, Copenhagen University, Blegdamsvej 3, DK-2200 Copenhagen, Denmark
| | - Jean-François Hernandez
- Institut des Biomolécules Max Mousseron, UMR5247 CNRS, Universités Montpellier 1 and 2, Faculty of Pharmaceutical Sciences, 15 Avenue Charles Flahault, F-34093 Montpellier, France
| | - Bart De Spiegeleer
- Drug Quality and Registration (DruQuaR) group, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, B-9000 Ghent, Belgium.
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Ashmarin IP, Danilova RA, Rud'ko OI, Belopolskaya MV, Obukhova MF, Shmalgausen EV. An Immunochemical Approach to Model and Long-Term Suppression of Depressive and Anxiety Behavior. SPANISH JOURNAL OF PSYCHOLOGY 2014; 9:219-27. [PMID: 17120701 DOI: 10.1017/s1138741600006119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The inhibitor of monoaminooxydase isatin and the ligand of B-receptors cholecystokinin-4 play a significant role in the suppression and induction of depressive and anxiety states. We induced the formation of auto-antibodies to these compounds against their conjugates with antigen-carrier by immunization of white rats. The result was long-term (more than 2 months) stimulation of depressive and anxiety behavior after immunization to isatin and, in contrast, the suppression of such behavior after immunization to cholecystokinin. The perspective of immunochemical approach to long-term correction of behavior is discussed.
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Affiliation(s)
- Igor P Ashmarin
- Dept. of Human Physiology, School of Biology, Moscow State University, Vorobiovy Gory, Moscow 119922, Russia.
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Pan W, Stone KP, Hsuchou H, Manda VK, Zhang Y, Kastin AJ. Cytokine signaling modulates blood-brain barrier function. Curr Pharm Des 2013; 17:3729-40. [PMID: 21834767 DOI: 10.2174/138161211798220918] [Citation(s) in RCA: 164] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 08/30/2011] [Accepted: 09/26/2011] [Indexed: 02/06/2023]
Abstract
The blood-brain barrier (BBB) provides a vast interface for cytokines to affect CNS function. The BBB is a target for therapeutic intervention. It is essential, therefore, to understand how cytokines interact with each other at the level of the BBB and how secondary signals modulate CNS functions beyond the BBB. The interactions between cytokines and lipids, however, have not been fully addressed at the level of the BBB. Here, we summarize current understanding of the localization of cytokine receptors and transporters in specific membrane microdomains, particularly lipid rafts, on the luminal (apical) surface of the microvascular endothelial cells composing the BBB. We then illustrate the clinical context of cytokine effects on the BBB by neuroendocrine regulation and amplification of inflammatory signals. Two unusual aspects discussed are signaling crosstalk by different classes of cytokines and genetic regulation of drug efflux transporters. We also introduce a novel area of focus on how cytokines may act through nuclear hormone receptors to modulate efflux transporters and other targets. A specific example discussed is the ATP-binding cassette transporter-1 (ABCA-1) that regulates lipid metabolism. Overall, cytokine signaling at the level of the BBB is a crucial feature of the dynamic regulation that can rapidly change BBB function and affect brain health and disease.
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Affiliation(s)
- Weihong Pan
- Blood-Brain Barrier Group, Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA 70808, USA
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6
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Bolton C. Neurovascular damage in experimental allergic encephalomyelitis: a target for pharmacological control. Mediators Inflamm 2012; 6:295-302. [PMID: 18472862 PMCID: PMC2365877 DOI: 10.1080/09629359791415] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The blood-brain barrier (BBB) is composed of a continuous endothelial layer with pericytes and astrocytes in close proximity to offer homeostatic control to the neurovasculature. The human demyelinating disease multiple sclerosis and the animal counterpart experimental allergic encephalomyelitis (EAE) are characterized by enhanced permeability of the BBB facilitating oedema formation and recruitment of systemically derived inflammatory-type cells into target tissues to mediate eventual myelin loss and neuronal dysfunction. EAE is considered a useful model for examining the pathology which culminates in loss of BBB integrity and the disease is now proving valuable in assessing compounds for efficacy in limiting damage at neurovascular sites. The precise mechanisms culminating in EAE-induced BBB breakdown are unclear although several potentially disruptive mediators have been implicated and have been previously identified as potent effectors of cerebrovascular damage in non-disease related conditions of the central nervous system. The review considers evidence that common mechanisms may mediate cerebrovascular permeability changes irrespective of the initial insult and discusses therapeutic approaches for the control of BBB leakage in the demyelinating diseases.
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Affiliation(s)
- C Bolton
- Pharmacology Group, School of Pharmacy and Pharmacology, University of Bath, Bath, BA2 7AY UK.
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7
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Abstract
The blood-brain barrier (BBB) is comprised of the endothelial cells that line the capillaries of the brain. The unique characteristics of this barrier include tight intercellular junctions, a complex glycocalyx, a paucity of pinocytic vesicles, and an absence of fenestra. These properties allow for the selective exchange of substances between the systemic circulation and the extracellular fluid compartment of the brain. It is well established that there are many conditions, including those mediated by nitric oxide (NO), that can lead to an opening of the BBB, eventually leading to vasogenic edema and secondary brain damage. The precise molecular mechanisms mediating NO-induced tissue injury and the breakdown of the BBB are complex and not completely understood. NO is a soluble, easily diffusible gas that is generated by NO synthase. Two of the isoforms of NO synthase are constitutive, calcium-dependent enzymes that modulate many physiological functions, including the regulation of smooth muscle contraction and blood flow. The third isoform is calcium-independent and inducible and can be stimulated by stress, inflammation, and infection. Under these conditions, NO can be generated in large quantities and has detrimental effects on the CNS. NO has been shown to increase permeability of the BBB, allowing substances to enter into the brain passively. This review considers the role of NO and BBB integrity.
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Affiliation(s)
- V E Thiel
- Department of Pharmacology and Toxicology, University of Kansas, Lawrence 66045, USA
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8
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Sollertinskaya TN. Comparative physiological features of the regulatory effect of vasopressin on higher nervous activity in an ascending series of mammals. NEUROSCIENCE AND BEHAVIORAL PHYSIOLOGY 1997; 27:734-42. [PMID: 9406230 DOI: 10.1007/bf02461937] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
This report provides comparative physiological data on the features of the regulatory effects of the neurohormone vasopressin on higher nervous activity in an ascending series of mammals consisting of insectivores, rodents, and primates. Administration of vasopressin to hedgehogs produced a general facilitatory effect on conditioned reflex brain activity. The effects of vasopressin on memory processes in hedgehogs was minor. In rabbits, vasopressin had greater regulatory effects on conditioned reflex memory than in hedgehogs. However, this was transient in nature. In monkeys, administration of vasopressin had complex differential effects on simple conditioned responses and different types of memory. The effects of vasopressin on memory processes were long-lasting and were different for corticalized and noncorticalized forms of nervous activity. The question of changes in the nature of the regulatory effects of vasopressin during phylogenesis is discussed, as is the question of the increases in its level of involvement in the regulation of higher nervous functions and memory processes.
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Affiliation(s)
- T N Sollertinskaya
- Laboratory for the Comparative Physiology of the Cerebellum, I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg
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9
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de Lange EC, Bouw MR, Mandema JW, Danhof M, de Boer AG, Breimer DD. Application of intracerebral microdialysis to study regional distribution kinetics of drugs in rat brain. Br J Pharmacol 1995; 116:2538-44. [PMID: 8581296 PMCID: PMC1909064 DOI: 10.1111/j.1476-5381.1995.tb15107.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
1. The purpose of the present study was to determine whether intracerebral microdialysis can be used for the assessment of local differences in drug concentrations within the brain. 2. Two transversal microdialysis probes were implanted in parallel into the frontal cortex of male Wistar rats, and used as a local infusion and detection device respectively. Within one rat, three different concentrations of atenolol or acetaminophen were infused in randomized order. By means of the detection probe, concentration-time profiles of the drug in the brain were measured at interprobe distances between 1 and 2 mm. 3. Drug concentrations were found to be dependent on the drug as well as on the interprobe distance. It was found that the outflow concentration from the detection probe decreased with increasing lateral spacing between the probes and this decay was much steeper for acetaminophen than for atenolol. A model was developed which allows estimation of kbp/Deff (transfer coefficient from brain to blood/effective diffusion coefficient in brain extracellular fluid), which was considerably larger for the more lipohilic drug, acetaminophen. In addition, in vivo recovery values for both drugs were determined. 4. The results show that intracerebral microdialysis is able to detect local differences in drug concentrations following infusion into the brain. Furthermore, the potential use of intracerebral microdialysis to obtain pharmacokinetic parameters of drug distribution in brain by means of monitoring local concentrations of drugs in time is demonstrated.
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Affiliation(s)
- E C de Lange
- Leiden/Amsterdam Center for Drug Research, Division of Pharmacology, University of Leiden, The Netherlands
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Constantinescu CS, Ventura E, Hilliard B, Rostami A. Effects of the angiotensin converting enzyme inhibitor captopril on experimental autoimmune encephalomyelitis. Immunopharmacol Immunotoxicol 1995; 17:471-91. [PMID: 8576541 DOI: 10.3109/08923979509016382] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Angiotensin converting enzyme (ACE)1 mediates inflammation, participates in T cell stimulation by certain antigenic peptides, and influences the permeability of the blood brain barrier (BBB). ACE is elevated in multiple sclerosis (MS), an autoimmune disease of the central nervous system (CNS), characterized by increased BBB permeability. ACE inhibitor captopril suppresses certain immune functions and inhibits inflammatory or autoimmune diseases. We studied the effect of captopril on Lewis rat EAE, an animal model of MS. Fourteen rats with EAE were treated with captopril 30 mg/kg daily from immunization to day 21 post-immunization, and compared with 14 untreated rats. Severity scores and lymphocyte reactivity to myelin basic protein and mitogen were measured. There was a statistically significant (p < 0.05) difference between the mean and cumulative clinical scores of captopril-treated and untreated animals. Lymphocytes from captopril treated EAE rats at the peak of disease severity had diminished responses to MBP and concanavalin A. The data suggest a significant beneficial effect of captopril in Lewis rat EAE. Further studies including other inhibitors of ACE or of other peptidases with immune, inflammatory or BBB role, may identify potentially valuable immunopharmacologic agents.
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Affiliation(s)
- C S Constantinescu
- Department of Neurology, University of Pennsylvania, Philadelphia 19104, USA
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11
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de Lange EC, Danhof M, de Boer AG, Breimer DD. Critical factors of intracerebral microdialysis as a technique to determine the pharmacokinetics of drugs in rat brain. Brain Res 1994; 666:1-8. [PMID: 7889356 DOI: 10.1016/0006-8993(94)90276-3] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The purpose of this investigation was to determine the effect of experimental conditions on the concentrations of atenolol and acetaminophen in brain microdialysate, and to investigate the feasibility of performing repeated experiments within individual rats. Following intravenous bolus administration, reproducible concentration-time profiles were obtained in plasma and in brain dialysate. Based on corrections for in vitro recoveries of the intracerebral probe, the estimated ratio of the AUC in brain extracellular fluid (AUCbrain ECF) over the AUC in plasma (AUCplasma) +/- S.E.M. was 3.8 +/- 0.6% (n = 6) for atenolol and 18 +/- 2% (n = 6) for acetaminophen. Upon intracerebroventricular administration, interanimal differences in kinetics of acetaminophen in brain dialysate were observed while the concentrations of atenolol were below the detection limit of the assay. The influence of the use of isotonic versus hypotonic perfusate solutions on AUCbrain ECF values after intravenous bolus administration of both drugs was determined. Repeated experiments with the isotonic perfusate (24, 48 and 78 h post-surgery) resulted in AUCbrain ECF values with the ratio of 100: 98: 76% for acetaminophen and 100: 103: 98% for atenolol. Using a hypotonic perfusion solution the ratio of AUCbrain ECF values was 100: 154: 114% for acetaminophen and 100: 378: 427% for atenolol. A clear effect of the temperature of the hypotonic perfusate (24 vs 38 degrees C) on acetaminophen AUCbrain ECF values was revealed. The ratio of AUCbrain ECF values obtained at 24: 38 degrees C was 192: 100%.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- E C de Lange
- Leiden/Amsterdam Center for Drug Research, Division of Pharmacology, Sylvius Laboratory, The Netherlands
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12
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Moor AC, de Vries HE, de Boer AG, Breimer DD. The blood-brain barrier and multiple sclerosis. Biochem Pharmacol 1994; 47:1717-24. [PMID: 8204088 DOI: 10.1016/0006-2952(94)90297-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- A C Moor
- Division of Pharmacology, Leiden/Amsterdam Center for Drug Research, Sylvius Laboratories, University of Leiden, The Netherlands
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13
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Strand FL, Williams KA, Alves SE, Antonawich FJ, Lee TS, Lee SJ, Kume J, Zuccarelli LA. Melanocortins as factors in somatic neuromuscular growth and regrowth. Pharmacol Ther 1994; 62:1-27. [PMID: 7991638 DOI: 10.1016/0163-7258(94)90002-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Melanocortins, non-corticotropic fragments of adrenocorticotropic hormone, accelerate growth of the developing neuromuscular system and regrowth of damaged neurons, both in the adult and neonatal rat. Morphological, electrophysiological and behavioral characteristics are all improved by melanocortins, which, however, vary in potency, with alpha-MSH being the most effective. Tissue substrate, dosage, critical time periods and pattern of neuropeptide administration are all important variables. Melanocortins protect central neurons affecting motor behavior during development or following neuronal damage in the adult brain. Possible mechanisms of melanocortin action are discussed.
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Affiliation(s)
- F L Strand
- Biology Department, New York University, NY 10003
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14
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Banks WA, Kastin AJ, Sam HM, Cao VT, King B, Maness LM, Schally AV. Saturable efflux of the peptides RC-160 and Tyr-MIF-1 by different parts of the blood-brain barrier. Brain Res Bull 1994; 35:179-82. [PMID: 7953775 DOI: 10.1016/0361-9230(94)90100-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Peptides have been shown to be transported in the direction of both blood to brain and brain to blood. Although blood to brain transport is known to occur at both the choroid plexus and the capillary bed of the brain, comprising the two major components of the blood-brain barrier, the location of efflux systems for peptides remains largely unstudied. We adapted established methodologies to study this question for two peptides known to be transported out of the brain after injection into the cerebrospinal fluid (CSF): Tyr-MIF-1, transported by peptide transport system (PTS)-1 and RC-160, a somatostatin analog transported by PTS-5. Radioactive iodide, known to be transported out of the brain primarily by the capillaries, also was studied. We found that after injection into brain tissue, RC-160 and iodide were rapidly transported out of the brain by saturable mechanisms. By contrast, efflux of Tyr-MIF-1 was slow and nonsaturable after injection into brain tissue, but rapid and saturable after injection into the lateral ventricle of the brain. Autoradiography confirmed that peptide injected into brain tissue did not diffuse far from the site of injection during the study period. The results indicate that the efflux system for RC-160 is located at least partly at the capillaries and suggest that the major location for the efflux system of Tyr-MIF-1 is at the choroid plexus.
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Affiliation(s)
- W A Banks
- Veterans Affairs Medical Center-New Orleans, LA 70146
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15
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Affiliation(s)
- J Brownlees
- Division of Biochemistry, School of Biology and Biochemistry, Queen's University, Belfast, Northern Ireland, U.K
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16
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Broadwell RD. Endothelial cell biology and the enigma of transcytosis through the blood-brain barrier. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1993; 331:137-41. [PMID: 8333328 DOI: 10.1007/978-1-4615-2920-0_22] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- R D Broadwell
- Division of Neurological Surgery, University of Maryland School of Medicine, Baltimore 21201
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17
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Banks WA, Audus KL, Davis TP. Permeability of the blood-brain barrier to peptides: an approach to the development of therapeutically useful analogs. Peptides 1992; 13:1289-94. [PMID: 1494505 DOI: 10.1016/0196-9781(92)90037-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Peptides have been shown in both in vivo and in vitro systems to cross the blood-brain barrier (BBB) and so affect function on the side contralateral to their origin. Some peptides cross primarily by transmembrane diffusion, a nonsaturable mechanism largely dependent on the lipid solubility of the peptide. Other peptides are transported by saturable systems across the BBB. These transport systems can be in the CNS to blood direction, as in the cases of Tyr-MIF-1 and methionine enkephalin, in the blood to CNS direction, as in the case of peptide T, or bidirectional, as in the case of LHRH. Other factors that also affect the amount of peptide crossing the BBB include binding in blood, volume of distribution, enzymatic resistance, and half-time disappearance from the blood. An in vitro model of the BBB has been characterized and used to confirm that peptides can cross the BBB. Results with the model agree with those obtained in vivo and have been used to study the permeability of the BBB to peptides, the effect of peptides on BBB integrity, the cellular pathway peptides and proteins use to cross the BBB, and the ability of the BBB to degrade peptides. The in vivo and in vitro methods have been used together to develop halogenated enkephalin analogs that are enzymatically resistant, cross the BBB readily to accumulate in areas of the brain rich in opiate receptors, and are powerful analgesics.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- W A Banks
- Veterans Affairs Medical Center, New Orleans, LA 70146
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18
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Banks WA, Kastin AJ, Barrera CM. Delivering peptides to the central nervous system: dilemmas and strategies. Pharm Res 1991; 8:1345-50. [PMID: 1798668 DOI: 10.1023/a:1015884603456] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Peptides have been shown to cross the blood-brain barrier (BBB) as intact molecules so that they can influence the central nervous system. Peptides cross by saturable and nonsaturable mechanisms in the direction of both brain to blood and blood to brain. Passage of peptides, especially by saturable transport, has been shown to be influenced by pharmacological agents and physiological events. These findings support the view that peptides or their analogues could be useful as therapeutic agents for disorders of the central nervous system. They also suggest strategies in approaching therapeutic goals, including manipulating transport rates, targeting diseases due to altered BBB-peptide interactions, and designing analogues capable of taking advantage of such mechanisms of passage as paracellular transmembrane diffusion and brain-to-blood transport.
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Abstract
The last decade has seen rapid growth in research with neuropeptides. During this time, we have been actively developing several concepts including the highly controversial one that peptides can cross the blood-brain barrier in intact form. One of the endogenous brain peptides used as a prototype for that concept, Tyr-MIF-1, also was used for the concept of the existence of endogenous antiopiate neuropeptides. As has been true for most novel developments in science, these concepts, as well as some older ones, were met with a great deal of skepticism when first suggested. Eventually, however, amnesia concerning the difficulties initially encountered with the introduction of new concepts occurs, with their subsequent "rediscovery" made easier.
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Affiliation(s)
- A J Kastin
- Veterans Administration Medical Center, University of New Orleans, Louisiana
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Johansson BB. The physiology of the blood-brain barrier. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1990; 274:25-39. [PMID: 2239426 DOI: 10.1007/978-1-4684-5799-5_2] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The BBB is a dynamic interface between blood and the central nervous system enabling the brain to keep an optimal internal environment. The endothelial cells of the brain capillaries are unique epithelial-like cells that are fused together by tight junctions and have a low pinocytotic activity. The entry of a specific substance will, therefore, mainly depend on its lipid solubility, and whether or not it has access to any of the carriers in the endothelial cells. Enzymatic degradation in the endothelium can prevent entry into the brain of substances that do enter the endothelial cells. Astrocytes may have an important role by inducing and upholding some barrier functions. An intact BBB is evidently important for optimal brain function. Manipulation of the BBB to allow entry of therapeutic agents may be justified under certain circumstances but should be done with caution until we know more about the long-term consequences of such manipulation.
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Banks WA, Kastin AJ. Effect of neurotransmitters on the system that transports Tyr-MIF-1 and the enkephalins across the blood-brain barrier: a dominant role for serotonin. Psychopharmacology (Berl) 1989; 98:380-5. [PMID: 2568658 DOI: 10.1007/bf00451691] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Neurotransmitters and neuropeptides interact in several ways. We studied a new type of interaction: the effect of neurotransmitters on the saturable system that transports Tyr-MIF-1 and the enkephalins out of the central nervous system (CNS). The neurotransmitters were introduced into the lateral ventricle of the brain with radioiodinated peptide, using an established method previously shown to accurately quantify the amount of peptide being transported from the CNS to the blood. Serotonin inhibited transport, histamine stimulated transport, and dopamine, acetylcholine, epinephrine, GABA, kainic acid, cAMP and cGMP were without effect. Cyproheptadine, a serotonin antagonist, stimulated transport. Of several psychotropic agents tested, only tranylcypromine had a statistically significant effect and stimulated transport. Of the serotonin receptor specific agents tested, those with 5HT1 activity most consistently affected transport. We conclude that serotonin, and perhaps histamine, are important modulators of the system that transports Tyr-MIF-1 and the enkephalins out of the CNS.
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Affiliation(s)
- W A Banks
- Veterans Administration Medical Center, New Orleans, LA
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