Sildenafil citrate increases ocular blood flow and accelerates the rate of anterior chamber refilling after paracentesis. The latter effect could have resulted from a reduction in outflow facility or from an increase in aqueous humor (AH) production. In this study, we used scanning ocular fluorophotometry to examine the effects of sildenafil on AH turnover, and thus, AH production in eyes of live normal rabbits. For this, the rate of aqueous humor flow (AHF) was quantified with a commercially available fluorophotometer that measured the rate of fluorescein clearance from the anterior segment, which predominantly occurs via the trabecular meshwork. After ≈2 h of control scans to determine the baseline rate of AHF, the rabbits were fed 33 mg of sildenafil and allowed ≈45 min for the drug to enter the systemic circulation. Thereafter, fluorescence scans were retaken for an additional 90-120 min. Sildenafil ingestion increased AHF by about 36%, from 2.31 μL/min to 3.14 μL/min (P < 0.001, as two-tailed paired data, n = 20 eyes). This observation indicates that sildenafil citrate, which is a phosphodiesterase type-5 inhibitor currently marketed as a vasodilator (e.g., Viagra, Revatio), stimulates AHF in rabbits. Our results seem consistent with reports indicating that the drug dilates intraocular arteries and augments intraocular vascular flow. These physiological responses to the agent apparently led to increased fluid entry into the anterior chamber. As such, the drug might have utility in patients with ocular hypotony resulting from insufficient AH formation.
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http://dx.doi.org/10.1016/j.exer.2013.03.016 | DOI Listing |
Front Immunol
January 2025
Microbiology and Cell Science, Institute of Food and Agricultural Science, University of Florida, Gainesville, FL, United States.
Introduction: Recurrent uveitis (RU), an autoimmune disease, is a leading cause of ocular detriment in humans and horses. Equine and human RU share many similarities including spontaneous disease and aberrant cytokine signaling. Reduced levels of SOCS1, a critical regulator of cytokine signaling, is associated with several autoimmune diseases.
View Article and Find Full Text PDFBiochem Genet
January 2025
Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
One in 16, 000 live births is affected by the retinal tumor RB (retinoblastoma), which is frequently found in a child's early years. Both of the RB1 alleles that have been locally mutated in the affected retina are present in 60 percent of cases. Retinoblastoma (RB) can be detected using a variety of techniques, including imaging of the brain and orbits, eye examinations under anesthesia (EUAs), and the discovery of cell-free tumor DNA in samples of aqueous humor or plasma.
View Article and Find Full Text PDFPathogens
January 2025
Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise 'G. Caporale', National Reference Center for Brucellosis, 64100 Teramo, Italy.
Rose Bengal antigen and smooth lipopolysaccharide (s-LPS) were produced from a field strain of ("homologous" antigens) and from the reference strain S99 ("heterologous" antigens); they are currently used for the diagnosis of brucellosis in cattle, water buffaloes, sheep, goats, and pigs, as recommended in the Manual of Diagnostic Tests and Vaccines for Terrestrial Animals of the World Organization for Animal Health (WOAH). "Homologous" and "heterologous" antigens were used in a rapid serum agglutination test (Rose Bengal test, RBT) and a competitive ELISA assay (c-ELISA) to test a panel of sera, blood, and other body fluids (cerebrospinal fluid, pericardial fluid, tracheal fluid, and aqueous humor) collected from 71 individuals belonging to five cetacean species (; ; ; ; and ), which were found stranded on the Italian coastline. Six animals were positive for spp.
View Article and Find Full Text PDFInt J Mol Sci
January 2025
Department of Ophthalmology, Penn State University, Hershey, PA 17033, USA.
Extracellular vesicles (EVs) are lipid bilayer particles released by virtually all cells, with prominent roles in both physiological and pathological processes. The size, number, and molecular composition of released EVs correlate to the cells of origin, modulated by the cell's environment and pathologic state. The proteins, DNA, RNA, and protein cargo carried by EVs are protected by degradation, with a prominent role in targeted intercellular signaling.
View Article and Find Full Text PDFInt J Mol Sci
January 2025
Division of Clinical Pharmacology, Department of Pharmacology, Jichi Medical University, Shimotsuke-shi 329-0498, Tochigi, Japan.
Aflibercept and brolucizumab, two anti-VEGF agents used as intravitreal injections in ophthalmology, differ significantly in molecular weight (aflibercept-115 kDa and brolucizumab-26 kDa). Using aqueous humor samples collected after drug administration, we measured and performed a comparative analysis of pharmacokinetics and half-lives of these drugs in the human eye. Since the quantification of monoclonal antibodies (mAbs) using antigen-antibody reactions, such as ELISA, is influenced by endogenous ligands or anti-drug antibodies, we employed nano-surface and molecular-orientation limited proteolysis (nSMOL), combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS), for accurate measurements.
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