scholarly journals Transfer of rhodamine-123 into the brain and cerebrospinal fluid of fetal, neonatal and adult rats

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Liam M. Koehn ◽  
Katarzyna M. Dziegielewska ◽  
Mark D. Habgood ◽  
Yifan Huang ◽  
Norman R. Saunders
Keyword(s):  
Cerebrospinal Fluid ◽  
Fetal Brain ◽  
Maternal Blood ◽  
Adult Brain ◽  
Rhodamine 123 ◽  
Patient Specific ◽  
Adult Rats ◽  
Blood Brain ◽  
The Brain ◽  
Brain Barriers

Abstract Background Adenosine triphosphate binding cassette transporters such as P-glycoprotein (PGP) play an important role in drug pharmacokinetics by actively effluxing their substrates at barrier interfaces, including the blood-brain, blood-cerebrospinal fluid (CSF) and placental barriers. For a molecule to access the brain during fetal stages it must bypass efflux transporters at both the placental barrier and brain barriers themselves. Following birth, placental protection is no longer present and brain barriers remain the major line of defense. Understanding developmental differences that exist in the transfer of PGP substrates into the brain is important for ensuring that medication regimes are safe and appropriate for all patients. Methods In the present study PGP substrate rhodamine-123 (R123) was injected intraperitoneally into E19 dams, postnatal (P4, P14) and adult rats. Naturally fluorescent properties of R123 were utilized to measure its concentration in blood-plasma, CSF and brain by spectrofluorimetry (Clariostar). Statistical differences in R123 transfer (concentration ratios between tissue and plasma ratios) were determined using Kruskal-Wallis tests with Dunn’s corrections. Results Following maternal injection the transfer of R123 across the E19 placenta from maternal blood to fetal blood was around 20 %. Of the R123 that reached fetal circulation 43 % transferred into brain and 38 % into CSF. The transfer of R123 from blood to brain and CSF was lower in postnatal pups and decreased with age (brain: 43 % at P4, 22 % at P14 and 9 % in adults; CSF: 8 % at P4, 8 % at P14 and 1 % in adults). Transfer from maternal blood across placental and brain barriers into fetal brain was approximately 9 %, similar to the transfer across adult blood-brain barriers (also 9 %). Following birth when placental protection was no longer present, transfer of R123 from blood into the newborn brain was significantly higher than into adult brain (3 fold, p < 0.05). Conclusions Administration of a PGP substrate to infant rats resulted in a higher transfer into the brain than equivalent doses at later stages of life or equivalent maternal doses during gestation. Toxicological testing of PGP substrate drugs should consider the possibility of these patient specific differences in safety analysis.

scholarly journals Transfer of Rhodamine-123 into the Brain and Cerebrospinal Fluid of Fetal, Neonatal and Adult Rats

2020 ◽  
Author(s):  
Liam Koehn ◽  
Katarzyna M Dziegielewska ◽  
Mark D Habgood ◽  
Yifan Huang ◽  
Norman R Saunders
Keyword(s):  
Cerebrospinal Fluid ◽  
Plasma Concentrations ◽  
Maternal Blood ◽  
Adult Brain ◽  
Rhodamine 123 ◽  
Patient Specific ◽  
Adult Rats ◽  
Blood Brain ◽  
The Brain ◽  
Brain Barriers

Abstract Background: Adenosine triphosphate binding cassette transporters such as P-glycoprotein (PGP) play an important role in drug pharmacokinetics by actively effluxing their substrates at barrier interfaces, including the blood-brain, blood-cerebrospinal fluid (CSF) and placental barriers. For a molecule to access the brain during fetal stages it must bypass efflux transporters at both the placental barrier and brain barriers themselves. Following birth, placental protection is no longer present and brain barriers remain the major line of defense. Understanding developmental differences that exist in the transfer of PGP substrates into the brain is important for ensuring that medication regimes are safe and appropriate for all patients. Methods: In the present study PGP substrate rhodamine-123 (R123) was injected intraperitoneally into E19 dams, postnatal (P4, P14) and adult rats. Naturally fluorescent properties of R123 were utilized to measure its concentration in blood-plasma, CSF and brain by spectrofluorimetry (Clariostar). Statistical differences in R123 transfer (ratios between tissue and plasma concentrations) were determined using Kruskal-Wallis tests with Dunn’s corrections. Results: Following maternal injection the transfer of R123 across the E19 placenta from maternal blood to fetal blood was around 20%. Of the R123 that reached fetal circulation 41% transferred into brain and 38% into CSF. The transfer of R123 from blood to brain and CSF was lower in postnatal pups and decreased with age (brain: 43% at P4, 22% at P14 and 9% in adults; CSF: 8% at P4, 8% at P14 and 1% in adults). Transfer from maternal blood across placental and brain barriers into fetal brain was approximately 8%, similar to the transfer across adult blood-brain barriers (9%). Following birth when placental protection was no longer present, transfer of R123 from blood into the newborn brain was significantly higher than into adult brain (3 fold, p<0.05). Conclusions: Administration of a PGP substrate to infant rats resulted in a higher transfer into the brain than equivalent doses at later stages of life or equivalent maternal doses during gestation. Toxicological testing of PGP substrate drugs should consider the possibility of these patient specific differences in safety analysis. Trial Registration: N/A.

scholarly journals The Potential Roles of Blood–Brain Barrier and Blood–Cerebrospinal Fluid Barrier in Maintaining Brain Manganese Homeostasis

Nutrients ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1833
Author(s):  
Shannon Morgan McCabe ◽  
Ningning Zhao
Keyword(s):  
Cerebrospinal Fluid ◽  
Blood Brain Barrier ◽  
Blood Circulation ◽  
Critical Role ◽  
Systemic Circulation ◽  
Brain Parenchyma ◽  
Brain Barrier ◽  
Blood Brain ◽  
The Brain

Manganese (Mn) is a trace nutrient necessary for life but becomes neurotoxic at high concentrations in the brain. The brain is a “privileged” organ that is separated from systemic blood circulation mainly by two barriers. Endothelial cells within the brain form tight junctions and act as the blood–brain barrier (BBB), which physically separates circulating blood from the brain parenchyma. Between the blood and the cerebrospinal fluid (CSF) is the choroid plexus (CP), which is a tissue that acts as the blood–CSF barrier (BCB). Pharmaceuticals, proteins, and metals in the systemic circulation are unable to reach the brain and spinal cord unless transported through either of the two brain barriers. The BBB and the BCB consist of tightly connected cells that fulfill the critical role of neuroprotection and control the exchange of materials between the brain environment and blood circulation. Many recent publications provide insights into Mn transport in vivo or in cell models. In this review, we will focus on the current research regarding Mn metabolism in the brain and discuss the potential roles of the BBB and BCB in maintaining brain Mn homeostasis.

The impact of hypoxia on blood-brain, blood-CSF and CSF-brain barriers

2021 ◽  
Author(s):  
Jeff F. Dunn ◽  
Albert M Isaacs
Keyword(s):  
Multiple Sclerosis ◽  
Cerebrospinal Fluid ◽  
Cellular Structures ◽  
Bacterial Toxin ◽  
Blood Brain ◽  
High Altitude Cerebral Edema ◽  
The Central Nervous System ◽  
Neurological Conditions ◽  
The Impact ◽  
Brain Barriers

The blood-brain barrier (BBB), blood-cerebrospinal fluid barrier (BCSFB) and CSF-brain barriers (CSFBB) are highly regulated barriers in the central nervous system comprising of complex multi-cellular structures that separate nerves and glia from blood and cerebrospinal fluid, respectively. Barrier damage has been implicated in the pathophysiology of diverse hypoxia-related neurological conditions including stroke, multiple sclerosis, hydrocephalus and high-altitude cerebral edema. Much is known about damage to the BBB in response to hypoxia but much less is known about the BCSFB and CSFBB. Yet it is known that these other barriers are implicated in damage after hypoxia or inflammation. In the 1950s, it was shown that the rate of radionucleated human serum albumin passage from plasma to CSF was 5-times higher during hypoxic than normoxic conditions in dogs, due to blood-CSF barrier disruption. Severe hypoxia due to administration of the bacterial toxin, lipopolysaccharide (LPS) is associated with disruption of the CSFBB. This review discusses the anatomy of the BBB, BCSFB and CSFBB, and the impact of hypoxia and associated inflammation on the regulation of those barriers.

scholarly journals Age-Associated Changes in the Immune System and Blood–Brain Barrier Functions

2019 ◽  
Vol 20 (7) ◽  
pp. 1632 ◽  
Author(s):  
Michelle Erickson ◽  
William Banks
Keyword(s):  
Central Nervous System ◽  
Immune System ◽  
Blood Brain Barrier ◽  
Neurological Disorders ◽  
Brain Barrier ◽  
Immune Functions ◽  
Blood Brain ◽  
The Brain ◽  
Brain Barriers

Age is associated with altered immune functions that may affect the brain. Brain barriers, including the blood–brain barrier (BBB) and blood–CSF barrier (BCSFB), are important interfaces for neuroimmune communication, and are affected by aging. In this review, we explore novel mechanisms by which the aging immune system alters central nervous system functions and neuroimmune responses, with a focus on brain barriers. Specific emphasis will be on recent works that have identified novel mechanisms by which BBB/BCSFB functions change with age, interactions of the BBB with age-associated immune factors, and contributions of the BBB to age-associated neurological disorders. Understanding how age alters BBB functions and responses to pathological insults could provide important insight on the role of the BBB in the progression of cognitive decline and neurodegenerative disease.

Antimicrobial Penetration into Cerebrospinal Fluid

1981 ◽  
Vol 15 (5) ◽  
pp. 341-368 ◽  
Author(s):  
Mark L. Richards ◽  
Randall A. Prince ◽  
Karen A. Kenaley ◽  
Jeanine A. Johnson ◽  
Jack L. LeFrock
Keyword(s):  
Cerebrospinal Fluid ◽  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Cns Infections ◽  
Blood Brain ◽  
The Brain

The complex physiology of the blood-brain barrier and the characteristics of an antimicrobial which govern its distribution into the brain are poorly understood. Likewise, available data regarding CSF antimicrobial concentrations after extra-CNS administration, as tabulated in this review, are inadequate. Because of the potentially dire consequences that result from inappropriately treated CNS infections, large cooperative studies using standardized methodology are needed. Suggestions for such methods are outlined.

scholarly journals THE EFFECT OF POLIOMYELITIS VIRUS ON HUMAN BRAIN CELLS IN TISSUE CULTURE

1955 ◽  
Vol 102 (1) ◽  
pp. 29-36 ◽  
Author(s):  
M. J. Hogue ◽  
R. McAllister ◽  
A. E. Greene ◽  
L. L. Coriell
Keyword(s):  
Tissue Culture ◽  
Human Brain ◽  
Cell Body ◽  
Good Condition ◽  
Fetal Brain ◽  
Adult Brain ◽  
Brain Cells ◽  
Poliomyelitis Virus ◽  
The Individual ◽  
The Brain

Poliomyelitis virus I, Mahoney strain, affected human brain cells grown in tissue cultures usually causing death of the cells in 3 days. The neurons reacted in different ways to the virus, some died with their neurites extended, others contracted one or more of their neurites. Terminal bulbs were frequently formed at the tips of the neurites when they were being drawn into the cell body. The final contraction of the cell body and the change into a mass of granules were often very sudden. Vacuoles often developed in the neuron. There was no recovery. Astrocytes, oligodendroglia, and macrophages were affected by the virus but not as quickly as the neurons. The age of the tissue culture was not a factor when the cells were in good condition. The age of the individual donor of the brain tissue was a factor; the fetal brain cells appeared to be more sensitive to the virus than the adult brain cells. The fetal neurons often reacted ½ hour after inoculation while the adult neurons reacted more slowly, 2 to 24 hours after inoculation. All these changes seemed to be caused by virus infection because they were prevented by specific antiserum or by preheating the virus.

Inhibition of P-glycoprotein Activity at the Primate Blood-Brain Barrier Increases the Distribution of Nelfinavir into the Brain but Not into the Cerebrospinal Fluid

2007 ◽  
Vol 35 (9) ◽  
pp. 1459-1462 ◽  
Author(s):  
Amal Kaddoumi ◽  
Sung-Up Choi ◽  
Loren Kinman ◽  
Dale Whittington ◽  
Che-Chung Tsai ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Blood Brain Barrier ◽  
Brain Barrier ◽  
P Glycoprotein ◽  
Blood Brain ◽  
The Brain

scholarly journals Transfer Constants for Blood-Brain Barrier Permeation of the Neuroexcitatory Shellfish Toxin, Domoic Acid

1991 ◽  
Vol 18 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Edward Preston ◽  
Ivo Hynie
Keyword(s):  
Blood Brain Barrier ◽  
Domoic Acid ◽  
Carrier Transport ◽  
Polar Compounds ◽  
Brain Regions ◽  
Brain Barrier ◽  
Adult Rats ◽  
Mean Values ◽  
Blood Brain ◽  
The Brain

ABSTRACT:The cause of the toxic mussel poisoning episode in 1987 was traced to a plankton-produced excitotoxin, domoic acid. Experiments were undertaken to quantitate the degree to which blood-borne domoic acid can permeate the microvasculature to enter the brain. Pentobarbital-anesthetized, adult rats received an i.v. injection of 3H-domoic acid which was permitted to circulate for 3-60 min. Transfer constants (Ki) describing blood-to-brain diffusion of tracer were calculated from analysis of the relationship between brain vs plasma radioactivity with time. Mean values (mL.g-1.s-1 x 106) for permeation into 7 brain regions (n = 10 rats) ranged from 1.60 ± 0.13 (SE) to 1.86 ± 0.33 (cortex, ponsmedulla respectively), and carrier transport or regional selectivity in uptake were not evident. Nephrectomy prior to domoic acid injection resulted in the elevation of circulating plasma tracer level and brain uptake. The Ki values are comparable to those for other polar compounds such as sucrose, and indicate that the blood-brain barrier greatly limits the amount of toxin that enters the brain. Together with absorbed dosage, integrity of the cerebrovascular barrier and normal kidney function are important to the outcome of accidentally ingesting domoic acid.

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