title: Stimulatory effects of ascorbic acid on hyaluronic acid synthesis of in vitro cultured normal and glaucomatous trabecular meshwork cells of the human eye.
abstract: The outflow of aqueous humor of the primate eye occurs across the filter system of the trabecular meshwork (TM) into Schlemm's canal. Cells of TM derived from a normal (TM-N-cells) and a glaucomatous human eye (TM-G-cells) were established in monolayer culture. The present comparative experiments were performed with cells kept in a defined serum-free medium (the aqueous humor is nearly protein-free!). Under these conditions the cells stay alive for several months in a non-proliferating state. TM-G-cells exhibited a lower synthesis rate of glycosaminoglycans-especially of hyaluronic acid (HA)--than TM-N-cells. Addition of 50-200 micrograms/ml ascorbic acid (the aqueous humor is characterized by a high ascorbic acid concentration of about 150 micrograms/ml) to the culture medium resulted in a significant dose-dependent stimulation of HA-synthesis and secretion, which was relatively stronger in case of TM-G-cells than with TM-N-cells. Thus, the results suggest a role of ascorbic acid in the probably membrane-localized HA-synthesis. Functions of ascorbic acid and HA for the morphological and functional integrity of the TM-cells in vitro and the outflow apparatus in vivo were discussed.
authors.affiliation: Institut für Physiologische Chemie, Philipps-Universität Marburg, Germany.
authors.forename: D O
authors.initials: DO
authors.lastname: Schachtschabel
authors.forename: E
authors.initials: E
authors.lastname: Binninger
mesh_terms: D000328:Adult; D001082:Aqueous Humor / Q000187:drug effects* / Q000502:physiology; D001205:Ascorbic Acid / Q000494:pharmacology* / Q000502:physiology; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000187:drug effects* / Q000502:physiology; D003094:Collagen / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D005902:Glaucoma, Open-Angle / Q000473:pathology*; D006025:Glycosaminoglycans / Q000096:biosynthesis; D006801:Humans; D006820:Hyaluronic Acid / Q000096:biosynthesis*; D007429:Intraocular Pressure / Q000187:drug effects / Q000502:physiology; D008875:Middle Aged; D013268:Stimulation, Chemical; D014129:Trabecular Meshwork / Q000187:drug effects* / Q000473:pathology
chemical_list: D006025:Glycosaminoglycans; D006820:Hyaluronic Acid; D003094:Collagen; D001205:Ascorbic Acid