Abstract:
:The transport rates of radiolabeled ascorbic acid and dehydroascorbic acid, as well as, labeled 3-O-methyl-D-glucose and L-glucose from a central plasma compartment into aqueous and vitreous humors and cerebrospinal fluid were studied in vivo. Normal, male albino Sprague-Dawley rats and English Short Haired guinea pigs were used to explore the mechanism of ascorbic acid entry into ocular humors in a species that can produce ascorbate (the rat) and one that cannot and, like humans, is dependent on dietary sources (the guinea pig). In vivo kinetic studies allowed for the calculation of entry rate constants, Ki (min-1), in double-labeled experiments using L-glucose as an internal passive control. Parallel TLC chromatographic studies were performed to monitor intraocular labeled molecules deriving from the plasma-introduced test molecule. In addition, resting levels of ascorbic acid and D-glucose were determined in order to obtain more reliable data than previously available. Resting levels of D-glucose revealed a consistent pattern of lower levels in aqueous and vitreous humors and CSF than found in plasma for both rat and guinea pig. However, ascorbate levels differed significantly, with the guinea pig demonstrating high ascorbate levels in the aforementioned humors: 58, 77 and 22, respectively, times the circulating plasma value of 0.2 +/- 0.2 mg/dl. In contrast, the rat, like the guinea pig, had low plasma ascorbate levels (3.3 +/- 0.8 mg/dl) compared to glucose (162 +/- 8 mg/dl), with even lower aqueous and vitreous values in a pattern similar to that of D-glucose. In vivo aqueous, vitreous and CSF transport results from the guinea pig indicate active transport mechanisms for ascorbic acid that prefer the ascorbate over the dehydroascorbate moiety and are probably different from the carrier-facilitated diffusion mechanisms for D-glucose, which do not move molecules against a concentration gradient. TLC studies, performed under nitrogen, revealed that only (14C)-ascorbic acid was present in aqueous or vitreous humors regardless of whether the radiolabeled pulse was of ascorbic or dehydroascorbic acid. The rat demonstrated little or no carrier involvement, with ascorbic acid crossing into ocular humors at rates very close to those of L-glucose, which is similar in size and is considered to cross the barriers studied via passive diffusion. Saturation studies with unlabeled glucose and glucose inhibitor drugs phloretin (10(-3) M) and phloridzin (10(-1)) had no apparent effect on ocular entry rates. Dehydroascorbic acid movement was also found to be passive.(ABSTRACT TRUNCATED AT 400 WORDS)
journal_name
Invest Ophthalmol Vis Scijournal_title
Investigative ophthalmology & visual scienceauthors
DiMattio Jsubject
Has Abstractpub_date
1989-11-01 00:00:00pages
2320-31issue
11eissn
0146-0404issn
1552-5783journal_volume
30pub_type
杂志文章abstract:Purpose:To compare the changes in human tear proteome and clinical effects following topical cyclosporine A (CsA) 0.05% or diquafosol tetrasodium (DQS) 3% treatment of dry eye disease (DED), and to identify biomarkers for determining disease severity and treatment effectiveness in DED. Methods:A total of 18 patients w...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章,多中心研究,随机对照试验
doi:10.1167/iovs.19-27872
更新日期:2019-12-02 00:00:00
abstract::A group of 32 patients with low vision who were considered clinically appropriate candidates for visual rehabilitation with telescopic spectacles were prospectively studied before the first attempted use of these visual aids. Laboratory measurements were made of: (1) rotational head stability in pitch and yaw during q...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:1991-09-01 00:00:00
abstract:PURPOSE:To investigate the role of angiopoietin-1 (Ang1) in choroidal neovascularization (CNV) and vascular leakage. METHODS:We generated laser-induced CNV in mice and measured the size of CNV and vascular leakage after intravitreal administration of Ang1. The expressions and distributions of endothelial junctional pr...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.14-13897
更新日期:2014-04-07 00:00:00
abstract:PURPOSE:To investigate the protective effect of pioglitazone on the rat retina after ischemia/reperfusion (I/R) injury and to explore its possible mechanisms. METHODS:Retinal ischemia was induced by increasing the intraocular pressure to 110 mm Hg for 60 minutes, and pioglitazone was delivered 3 hours before the I/R. ...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.13-11614
更新日期:2013-06-06 00:00:00
abstract:Purpose:Dry eye disease (DED) is a multifactorial disease associated with ocular surface inflammation. Toll-like receptors (TLRs) are integral in the initiation of inflammatory signaling. Therefore, we evaluated the effect of TLR-deficiency on dry eye-related ocular surface damage and inflammation using a mouse model o...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.17-23397
更新日期:2018-06-01 00:00:00
abstract:PURPOSE:To investigate the role of PalB and PacC, two components of a pH-responsive signal-transduction pathway of Aspergillus nidulans, during the pathogenesis of fungal infection of the cornea. METHODS:Fungal strains included an A. nidulans wild-type isolate (A83), loss-of-function A. nidulans mutants of the palB (B...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.09-4348
更新日期:2010-03-01 00:00:00
abstract:PURPOSE:To assess the aqueous outflow pathway in primary open-angle glaucoma (POAG) through provocative gonioscopy and channelography with a flexible microcatheter and fluorescein tracer during canaloplasty. METHODS:One eye each was randomly selected from 28 consecutive black African POAG patients undergoing canalopla...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.09-4327
更新日期:2010-03-01 00:00:00
abstract::We have investigated alterations of the metabolic state in vitamin A-deficient (A-) corneas using phosphorus-31 (31P) nuclear magnetic resonance (NMR) spectroscopy. Comparing to the control, A- corneas showed a prominent rise of phosphocreatine (PCr) as well as a total loss of glycerophosphorylcholine (GPC). Further, ...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:1989-04-01 00:00:00
abstract::Visual acuity of infants and young children with ophthalmologic disorders was assessed by adapting a transformed up-down staircase to preferential looking (PL) procedures. Eighty-five percent of pediatric patients between 11 days and 5 years of age were tested successfully. Acuity of infants and young children with no...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:1982-10-01 00:00:00
abstract:Purpose:To model the sensitivity of the optic nerve head (ONH) biomechanical environment to acute variations in IOP, cerebrospinal fluid pressure (CSFP), and central retinal artery blood pressure (BP). Methods:We extended a previously published numerical model of the ONH to include 24 factors representing tissue anato...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.17-22488
更新日期:2018-01-01 00:00:00
abstract:Purpose:Our goal was to generate and characterize a new mouse model in which only angiogenesis- and glaucoma-relevant tissues would be naturally fluorescent. The Matrix Gla (MGP) gene is highly expressed in vascular smooth muscle cells (VSMC) and trabecular meshwork (TM). We sought to direct our Mgp-Cre.KI mouse recomb...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.17-22992
更新日期:2018-02-01 00:00:00
abstract::The microvascular permeability response of the guinea pig conjunctiva to sulfidopeptide leukotrienes (LTs) was quantified as extravasation of radiolabeled bovine serum albumin. The LTs were potent inducers of increased microvascular permeability, with relative potencies LTE4 greater than or equal to LTD4 greater than ...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:1988-01-01 00:00:00
abstract:PURPOSE:Familial exudative vitreoretinopathy (FEVR) is a rare hereditary disorder characterized by the failure of peripheral retinal vascularization. The genes FZD4, LRP5, and TSPAN12 are known to be associated with the autosomal inheritance form of FEVR. In this study, we performed mutation screening for FZD4, LRP5, a...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.14-15680
更新日期:2015-08-01 00:00:00
abstract::Photoreceptor-mediated mechanisms were studied in patients with a recently identified retinopathy typified by night blindness, cystoid maculopathy, and similar scotopic and photopic electroretinograms (ERGs). Dark-adapted spectral sensitivity functions were only partly explained as composites of rod and cone curves sh...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:1990-05-01 00:00:00
abstract:PURPOSE:To determine the effect of treatment with latanoprost on the tissue inhibitors of metalloproteinase (TIMP)-1 and -2 in cultured human ciliary muscle (HCM) cells. METHODS:Confluent serum-starved HCM cells were exposed to increasing concentrations of latanoprost acid (LA, 1 nM to 10 micro M) for 6, 18, and 24 ho...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:2002-12-01 00:00:00
abstract:PURPOSE:To identify the risk factors for having advanced glaucomatous visual field loss on the first visit at three hospital eye services. METHODS:This was a hospital-based, case-control study involving patients newly diagnosed with glaucoma at first visit to one of three ophthalmic departments in the United Kingdom. ...
journal_title:Investigative ophthalmology & visual science
pub_type: 临床试验,杂志文章,多中心研究
doi:
更新日期:1999-09-01 00:00:00
abstract:PURPOSE:To investigate the effect of Fas and Fas ligand (FasL) deficiency on the development of herpes stromal keratitis and on the von Szily model of herpes retinitis in C57BL/6 mice, which are ordinarily resistant to development of both of these herpetic diseases. METHODS:Anterior chamber inoculation of the right ey...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:2001-10-01 00:00:00
abstract:PURPOSE:Cannabinoids have been reported to mediate changes in vascular resistance through endothelial receptor targets. We examined involvement of the endothelium in cannabinoid-mediated vasoactive responses in resistance arterioles of the retina. METHODS:Vascular responses to both intraluminal (IL) and extraluminal (...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.14-14879
更新日期:2015-06-01 00:00:00
abstract:PURPOSE:To investigate corneal nerve damage and its subsequent regeneration after excimer laser photokeratectomy in rabbit eyes. METHODS:Corneal photokeratectomy was performed on the right eyes of 34 pigmented rabbits, while the left eyes were used as a control. A Summit UV 200 excimer laser (Summit Technology, Waltha...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:1994-01-01 00:00:00
abstract::Experimental detachments were made in Dutch rabbit eyes by injecting autologous serum or Hanks' solution into the subretinal space through a glass micropipette. The serum was resorbed at a rate of 0.064 +/- 0.023 microliter/mm2/hr, which is approximately half as fast as Hanks' solution. Both cyclic GMP and dibutyryl c...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:1988-08-01 00:00:00
abstract:PURPOSE:To investigate the impact of diabetic macular ischemia (DMI) on visual acuity (VA), through the analysis of novel fluorescein angiography (FA) parameters. METHODS:Data were retrospectively collected over a 6-month period. DMI severity was graded using Early Treatment Diabetic Retinopathy Study (ETDRS) protocol...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.12-11103
更新日期:2013-03-28 00:00:00
abstract:PURPOSE:To determine whether the size and configuration of the optic chiasm in humans with albinism is different from that in normal control subjects. METHODS:Seventeen patients and 15 control subjects underwent magnetic resonance imaging of the entire head. Images were reformatted to the chiasm region and analyzed wi...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.02-0156
更新日期:2003-01-01 00:00:00
abstract:PURPOSE:To evaluate a fully automated local fractal dimension method to quantify vessel density and foveal avascular zone (FAZ) area in optical coherence tomography angiography (OCTA) images. METHODS:Fifty-two healthy Asian Indian eyes underwent imaging prospectively with OCTA system. Superficial and deep retinal vasc...
journal_title:Investigative ophthalmology & visual science
pub_type: 信件
doi:10.1167/iovs.15-18287
更新日期:2016-01-01 00:00:00
abstract:PURPOSE:Retinal ganglion cells die by apoptosis during development and after trauma such as axonal damage and exposure to excitotoxins. Apoptosis is associated with changes in the expression of genes that regulate this process. The genes that regulate apoptosis in retinal ganglion cells have not been characterized prim...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:1999-04-01 00:00:00
abstract:PURPOSE:The authors used and validated a recently developed method, mRNA differential display, to detect and clone genes that are differentially expressed in healing compared to stationary corneal epithelium. METHODS:RNAs from unwounded and 18-hour postwound corneal epithelia were isolated and subjected to mRNA differ...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:1995-09-01 00:00:00
abstract:PURPOSE:Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly. Evidence suggests oxidative stress plays a role in the disease. To assess the potential contribution of epigenetic regulation of antioxidant genes relevant to AMD pathogenesis, we evaluated DNA methylation, a tissue-specifi...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.11-8449
更新日期:2012-04-24 00:00:00
abstract:PURPOSE:To study the vasorelaxing effect of calcitonin gene-related peptide (CGRP) and natriuretic peptides on isolated bovine retinal arteries (BRAs) and to evaluate the possibility of the unidentified retinal relaxing factor (RRF) being one of these peptides. METHODS:Retinal arteries were isolated from bovine eyes a...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.04-1093
更新日期:2005-04-01 00:00:00
abstract:PURPOSE:This study explored the role of the left posterior parietal cortex (PPC) in saccades, vergence, and combined saccade-vergence movements by means of transcranial magnetic stimulation (TMS) in humans. METHODS:TMS was applied over the left PPC for 80, 90, or 100 ms after target onset. In a control experiment, TMS...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:10.1167/iovs.03-1291
更新日期:2004-07-01 00:00:00
abstract::Specimens for chlamydial isolation culture and direct fluorescent antibody cytology (DFA) were collected from 1671 women and children from a trachoma-endemic area in Central Tanzania. Trachoma was graded using the new World Health Organization grading scheme, and 54% of the children and 9% of the women had inflammator...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:1989-08-01 00:00:00
abstract:PURPOSE:The inhibition of angiogenesis by angiostatic steroids has been demonstrated in a variety of systems, including rabbit and rat cornea. There is considerable interest in the therapeutic potential of this class of compounds for angiogenic ocular conditions such as diabetic retinopathy, macular degeneration, and r...
journal_title:Investigative ophthalmology & visual science
pub_type: 杂志文章
doi:
更新日期:2001-01-01 00:00:00