Drugs vary in their ability to permeate the blood-retinal barrier (BRB), blood-aqueous humor barrier (BAB), and blood-brain barrier (BBB) and the factors affecting the drug permeation remain unclear. In this study, the permeability of various substances across BRB, BAB, and BBB in rats was determined using the brain uptake index (BUI), retinal uptake index (RUI), and aqueous humor uptake index (AHUI) methods. Lipophilic substances showed high permeabilities across BBB and BRB. The RUI values of these substances were approximately four-fold higher than the BUI values. The AHUI versus lipophilicity curve had a parabolic shape with AHUI(max) values at log D(7.4) ranging from -1.0 to 0.0. On the basis of the difference on the lipophilicities, verapamil, quinidine, and digoxin showed lower permeability than predicted from those across BBB and BRB, whereas only digoxin showed a lower permeability across BRB. These low permeabilities were significantly increased by P-glycoprotein inhibitors. Furthermore, anion transporter inhibition increased the absorption of digoxin to permeate into the retina and aqueous humor. In conclusion, this study suggests that efflux transport systems play an important role in the ocular absorption of drugs from the circulating blood after systemic administration.
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http://dx.doi.org/10.1002/jps.22610 | DOI Listing |
Int J Pharm
December 2024
Great Ormond Street Institute of Child Health, University College London, London WC1E 6BT, UK. Electronic address:
The neuronal ceroid lipofuscinoses, commonly known as Batten disease, are a group of lysosomal storage disorders affecting children. There is extensive central nervous system and retinal degeneration, resulting in seizures, vision loss and a progressive cognitive and motor decline. Enzyme replacement and gene therapies are being developed, and mRNA and oligonucleotide therapies are more recently being considered.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2024
Paris Cardiovascular Research Center, Université Paris Cité, Inserm U970, Paris F-75015, France.
The integrity of the blood-retina barrier (BRB) is crucial for phototransduction and vision, by tightly restricting transport of molecules between the blood and surrounding neuronal cells. Breakdown of the BRB leads to the development of retinal diseases. Here, we show that Netrin-1/Unc5b and Norrin/Lrp5 signaling establish a zonated endothelial cell gene expression program that controls BRB integrity.
View Article and Find Full Text PDFMetabolism
December 2024
School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea; Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul 06351, Republic of Korea; Biomedical Institute for Convergence, Sungkyunkwan University, Suwon 16419, Republic of Korea; Institute of Quantum Biophysics, Sungkyunkwan University, Suwon 16419, Republic of Korea. Electronic address:
Background: Diabetic retinopathy (DR), a major blindness cause in developed countries, is intricately linked to diabetes management and its duration. Here, we demonstrate that HDAC6 mediates NLRP3 inflammasome activation under diabetic conditions, leading to retinal inflammation and degeneration.
Methods: This study demonstrated the therapeutic effects of HDAC6 genetic ablation, pharmacological inhibition, and HDAC6-deficient bone marrow transplantation in a diabetes model induced by streptozotocin and a high-fat diet.
Curr Biol
December 2024
Synaptic Physiology Section, National Institute of Neurological Disorder and Stroke, National Institutes of Health, Bethesda, MD 20814, USA. Electronic address:
The neurovascular unit (NVU), comprising vascular, glial, and neural elements, supports the energetic demands of neural computation, but this aspect of the retina's trilaminar vessel network is poorly understood. Only the innermost vessel layer-the superficial vascular plexus (SVP)-is associated with astrocytes, like brain capillaries, whereas radial Müller glia interact with vessels in the other layers. Using serial electron microscopic reconstructions from mouse and primate retina, we find that Müller processes cover capillaries in a tessellating pattern, mirroring the wrapping of brain capillaries by tiled astrocytic endfeet.
View Article and Find Full Text PDFJ Clin Med
December 2024
Ophthalmic Research Unit "Santiago Grisolía"/Fisabio, 46017 Valencia, Spain.
Diabetic macular edema (DME) is a leading cause of vision impairment and blindness among diabetic patients, requiring effective diagnostic and monitoring strategies. This systematic review aims to synthesize current knowledge on molecular biomarkers associated with DME, focusing on their potential to improve diagnostic accuracy and disease management. A comprehensive search was conducted in PubMed, Embase, Medline, and the Cochrane Central Register of Controlled Trials, covering literature from 2004 to 2023.
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