kebaldwin
Mon, Nov-26-07, 06:06
Researchers at National Autonomous University have published new data on diabetic retinopathy
NewsRx.com
11-23-07
According to a study from Mexico, "Oxidative stress is an important causative factor in the pathogenesis of diabetic retinopathy (see also Diabetic Retinopathy). Therefore, it becomes important to understand the mechanisms that help maintain appropriate levels of a small molecule antioxidant such as ascorbate in the retina."
"The outer blood-banier which results from the tight junctions between the retinal pigment epithelial cells (RPE) restricts the flow of nutrients reaching the retina. In this study, we characterized the transport properties of carboxyl-C-14 ascorbate (AA) in normal rat retina and RPE, and compared them with those in streptozotocin-diabetic rats. Retina and RPE accumulated AA by a temperature-sensitive and energy-dependent kinetic mechanism with an apparent Km of 3 80 and 420 mc M, respectively. Accumulation of AA was significantly reduced in a sodium-free medium. Although high glucose concentrations reduced AA uptake by 40%, this was not affected by cytochalasin B. The RPE and retina of diabetic rats presented lower levels of AA accumulation," wrote R. Salceda and colleagues, National Autonomous University.
The researchers concluded: "These findings suggest the presence of the specific vitamin C transporter SVCT in retina and RPE, which may be involved in the manifestation of diabetic retinopathy."
Salceda and colleagues published their study in Comparative Biochemistry and Physiology C - Toxicology & Pharmacology (Ascorbate uptake in normal and diabetic rat retina and retinal pigment epithelium. Comparative Biochemistry and Physiology C - Toxicology & Pharmacology, 2007;146(1-2):175-179).
For more information, contact R. Salceda, National Autonomous University of Mexico, Institute Fisiol Celular, Dept. of Neurociencias, Apdo Postal 70-253, Mexico City 04510, DF, Mexico.
Publisher contact information for the journal Comparative Biochemistry and Physiology C - Toxicology & Pharmacology is: Elsevier Science Inc., 360 Park Avenue South, New York, NY 10010-1710, USA.
Keywords: Mexico, Diabetic Retinopathy, Ophthalmology, National Autonomous University.
This article was prepared by Angiogenesis Weekly editors from staff and other reports. Copyright 2007, Angiogenesis Weekly via NewsRx.com.
To see more of the NewsRx.com, or to subscribe, go to http://www.newsrx.com .
http://www.lef.org/news/LefDailyNews.htm?NewsID=6142&Section=Vitamins
NewsRx.com
11-23-07
According to a study from Mexico, "Oxidative stress is an important causative factor in the pathogenesis of diabetic retinopathy (see also Diabetic Retinopathy). Therefore, it becomes important to understand the mechanisms that help maintain appropriate levels of a small molecule antioxidant such as ascorbate in the retina."
"The outer blood-banier which results from the tight junctions between the retinal pigment epithelial cells (RPE) restricts the flow of nutrients reaching the retina. In this study, we characterized the transport properties of carboxyl-C-14 ascorbate (AA) in normal rat retina and RPE, and compared them with those in streptozotocin-diabetic rats. Retina and RPE accumulated AA by a temperature-sensitive and energy-dependent kinetic mechanism with an apparent Km of 3 80 and 420 mc M, respectively. Accumulation of AA was significantly reduced in a sodium-free medium. Although high glucose concentrations reduced AA uptake by 40%, this was not affected by cytochalasin B. The RPE and retina of diabetic rats presented lower levels of AA accumulation," wrote R. Salceda and colleagues, National Autonomous University.
The researchers concluded: "These findings suggest the presence of the specific vitamin C transporter SVCT in retina and RPE, which may be involved in the manifestation of diabetic retinopathy."
Salceda and colleagues published their study in Comparative Biochemistry and Physiology C - Toxicology & Pharmacology (Ascorbate uptake in normal and diabetic rat retina and retinal pigment epithelium. Comparative Biochemistry and Physiology C - Toxicology & Pharmacology, 2007;146(1-2):175-179).
For more information, contact R. Salceda, National Autonomous University of Mexico, Institute Fisiol Celular, Dept. of Neurociencias, Apdo Postal 70-253, Mexico City 04510, DF, Mexico.
Publisher contact information for the journal Comparative Biochemistry and Physiology C - Toxicology & Pharmacology is: Elsevier Science Inc., 360 Park Avenue South, New York, NY 10010-1710, USA.
Keywords: Mexico, Diabetic Retinopathy, Ophthalmology, National Autonomous University.
This article was prepared by Angiogenesis Weekly editors from staff and other reports. Copyright 2007, Angiogenesis Weekly via NewsRx.com.
To see more of the NewsRx.com, or to subscribe, go to http://www.newsrx.com .
http://www.lef.org/news/LefDailyNews.htm?NewsID=6142&Section=Vitamins