Functional Characterization of Carrier-Mediated Transport of Pravastatin across the Blood-Retinal Barrier in Rats
| Autor: | Kouichi Kawazu, Shinobu Fujii, Chikako Setoguchi, Ken Ichi Hosoya |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
Male
Microdialysis ATP Binding Cassette Transporter Subfamily B Blood–retinal barrier Pharmaceutical Science Pharmacology Blood–brain barrier Rats Sprague-Dawley Elimination rate constant Blood-Retinal Barrier polycyclic compounds medicine Animals Pravastatin biology Membrane transport protein Chemistry nutritional and metabolic diseases Biological Transport Rats Vitreous Body Probenecid medicine.anatomical_structure Blood-Brain Barrier biology.protein lipids (amino acids peptides and proteins) sense organs Efflux Rats Transgenic medicine.drug |
| Zdroj: | Drug Metabolism and Disposition. 43:1956-1959 |
| ISSN: | 1521-009X 0090-9556 |
| DOI: | 10.1124/dmd.115.066266 |
| Popis: | Systemically administered pravastatin effectively treats diabetic retinopathy without central nervous system side effects. The efflux transport mechanism of pravastatin from the brain has already been clarified. In this study, the influx of pravastatin across the blood-retinal and blood-brain barriers (BRB and BBB) and the efflux of pravastatin from the retina were investigated using rats. Pravastatin influx (blood-to-tissues) was assessed using the retinal and brain uptake index (RUI and BUI) methods, and microdialysis was performed to investigate the efflux (retina-to-blood) transport of pravastatin. The RUI and BUI values for [(3)H]pravastatin were lower than those expected based on its lipophilicity, suggesting that the influx transport across the BRB and BBB was less than the reverse-direction transport. The RUI and BUI values for [(3)H]pravastatin were significantly decreased by pravastatin, digoxin, and probenecid, indicating that pravastatin undergoes carrier-mediated influx transport in the blood-to-tissues direction across the BRB and BBB. After intravitreal injection, [(3)H]pravastatin and the bulk flow marker [(14)C]d-mannitol were found to be eliminated biexponentially from the vitreous humor. The elimination rate constant of [(3)H]pravastatin during the terminal phase was 1.66-fold greater than that of [(14)C]d-mannitol. Efflux transport was reduced in the retinal presence of pravastatin, digoxin, and benzylpenicillin, suggesting that pravastatin is transported via efflux transporters. In conclusion, pravastatin is transported across the BRB via uptake and efflux transporters in both the blood-to-retina and retina-to-blood directions, and the retina-to-blood transporters are dominant, based on the lower values of the RUI compared with the values expected from the lipophilicity. |
| Databáze: | OpenAIRE |
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