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Updated: May 14, 2026
Setting-up an In Vitro Model of Rat Blood-brain Barrier (BBB): A Focus on BBB Impermeability and Receptor-mediated Transport
Published on: June 28, 2014
In vitro blood-brain barrier models using brain capillary endothelial cells isolated from neonatal and adult rats
Fuyuko Takata1, Shinya Dohgu, Atsushi Yamauchi
1Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan.
Insights
Researchers developed a neonatal blood-brain barrier (BBB) model to study drug permeability in infants. This in vitro model accurately reflects age-related BBB differences, aiding in assessing neonatal drug safety and efficacy.
Area of Science:
- Neuroscience
- Pharmacology
- Developmental Biology
Background:
- The blood-brain barrier (BBB) protects the brain but hinders drug delivery.
- Neonatal brains are vulnerable due to an immature BBB.
- Existing in vitro BBB models do not accurately represent the neonatal BBB.
Purpose of the Study:
- To establish a neonatal in vitro BBB model that mimics age-related BBB properties.
- To compare BBB function in neonatal and adult models.
- To validate the model's predictive capacity using in vivo data.
Main Methods:
- Constructed neonatal and adult in vitro BBB models using rat brain endothelial cells.
- Assessed BBB function via transendothelial electrical resistance and permeability assays (sodium fluorescein, Evans blue-albumin).
- Evaluated P-glycoprotein (P-gp) function using rhodamine 123 transport and drug permeability studies in vitro and in vivo.
Main Results:
- The neonatal BBB model exhibited lower barrier integrity and P-gp function compared to the adult model.
- These functional differences correlated with reduced expression and altered distribution of barrier proteins and P-gp.
- The model accurately predicted higher in vivo BBB permeability for valproic acid in neonates, unlike nicotine.
Conclusions:
- An in vitro neonatal BBB model was successfully established.
- This model effectively simulates age-dependent BBB characteristics.
- The model can be used to assess age-dependent drug permeability and inform neonatal drug development.
Abstract:
The blood-brain barrier (BBB) restricts the entry of circulating drugs and xenobiotics into the brain, and thus its permeability to substances is a critical factor that determines their central effects. The infant brain is vulnerable to neurotoxic substances partly due to the immature BBB. The employment of in vitro BBB models to evaluate permeability of compounds provides higher throughput than that of in vivo animal experiments. However, existing in vitro BBB models have not been able to simulate the intrinsic neonatal BBB. To establish a neonatal BBB model that mimics age-related BBB properties, the neonatal and adult in vitro BBB models were constructed with brain endothelial cells isolated from 2- and 8-week-old rats, respectively. To evaluate BBB functions, transendothelial electrical resistance, permeability of sodium fluorescein and Evans blue-albumin, and transport of rhodamine123 were measured. Radiolabelled drugs were used for BBB permeability studies in the neonatal and adult BBB models (in vitro) and in age-matched rats (in vivo). The neonatal BBB model showed lower barrier and p-glycoprotein (P-gp) functions than the adult BBB model; these were well associated with lower expressions of the barrier-related proteins and P-gp, and a different distribution pattern of immunostained barrier-related proteins. Verapamil (a P-gp inhibitor) significantly increased the influx of rhodamine 123, supporting functional P-gp expression in the neonatal BBB model. Valproic acid, but not nicotine, showed higher BBB permeability in the neonatal BBB model, which was well in accordance with the in vivo BBB property. We established a neonatal BBB model in vitro. This could allow us to assess the age-dependent BBB permeability of drugs.
