Functional Characterization of Carrier-Mediated Transport of Pravastatin across the Blood-Retinal Barrier in Rats.
نویسندگان
چکیده
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.
منابع مشابه
Short Communication Functional characterization of carrier-mediated transport of pravastatin across the blood-retinal barrier in rats
متن کامل
Dmd066266 1956..1959
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 bloodretinal and blood-brain barriers (BRB and BBB) and the efflux of pravastatin from the retina were investigated using rats. Prava...
متن کاملIn situ kinetics of glucose transport across the blood-retinal barrier in normal rats and rats with streptozocin-induced diabetes.
Glucose transport across the blood-retinal barrier (BRB) was investigated in situ by means of a modification of the single-injection technique developed for studying transport across the blood-brain barrier. A retinal uptake index was calculated from the fractional extraction for 14C-glucose divided by the fractional extraction for the 3H2O reference. The use of the Eadie-Hofstee transformation...
متن کاملFunctional characterization of mouse organic anion transporting peptide 1a4 in the uptake and efflux of drugs across the blood-brain barrier.
This study investigated the role of a multispecific organic anion transporter, Oatp1a4/Slco1a4, in drug transport across the blood-brain barrier. In vitro transport studies using human embryonic kidney 293 cells expressing mouse Oatp1a4 identified the following compounds as Oatp1a4 substrates: pitavastatin (K(m) = 8.3 microM), rosuvastatin (K(m) = 12 microM), pravastatin, taurocholate (K(m) = 4...
متن کاملEffects of Pravastatin in Adriamycin-Induced Nephropathy in Rats
The aim of this study is to evaluate the effects of pravastatin on Adriamycin (ADR)-induced nephropathy and the mechanisms involved. Forty rats were divided into the following 4 groups: control, ADR (15 mg.kg-1, IP), ADR plus pravastatin (20 mg.kg-1 which was started 5 days prior to ADR injection), and ADR plus pravastatin (20 mg.kg-1 which was started 5 days after ADR injection). On day 20 aft...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Drug metabolism and disposition: the biological fate of chemicals
دوره 43 12 شماره
صفحات -
تاریخ انتشار 2015