PURPOSE: The purinergic P2Y(2) receptor agonists stimulate active Cl-transport across the excised rabbit conjunctival tissue in vitro. We determined whether UTP or ATP could increase the tear volume and change tear fluid composition in normal rabbits in vivo. METHODS: Fifty mL was applied to rabbit eyes of UTP, ATP at concentrations of 0.1, 0.3, 1, 3, 8.5% (1.8-154 mM) or saline. A modified Schirmer test with topical anesthesia was performed 5, 15, 30 and 60 min after the instillation. In studies lasting 30 days, 50 microL of 0.5% UTP was applied 6 times a day for 4 weeks. Tear samples were collected from the conjunctival sac with a glass microcapillary. The protein profile of the tear fluid was analyzed by SDS-polyacrylamide gel electrophoresis and total protein was measured with the Bradford assay. The Easy-Titer rabbit IgG assay kit was used for the determination of immunoglobulin G (IgG). RESULTS: UTP had dose-dependent stimulatory effects on tear secretion. It maximally increased tear secretion about 4-fold 15 min after its application. Similar effects were obtained with ATP. Repeated treatment with UTP reproducibly increased tear volume. Furthermore, UTP did not decrease total protein and IgG concentration in tear fluid and it had no effect on the protein profile. CONCLUSION: These data indicate that activation of P2Y(2) receptor increases tear fluid secretion accompanied with some proteins in normal rabbits. The purinergic agonists, UTP and ATP, have potential therapeutic value in the treatment of dry eye.
PURPOSE: The purinergic P2Y(2) receptor agonists stimulate active Cl-transport across the excised rabbit conjunctival tissue in vitro. We determined whether UTP or ATP could increase the tear volume and change tear fluid composition in normal rabbits in vivo. METHODS: Fifty mL was applied to rabbit eyes of UTP, ATP at concentrations of 0.1, 0.3, 1, 3, 8.5% (1.8-154 mM) or saline. A modified Schirmer test with topical anesthesia was performed 5, 15, 30 and 60 min after the instillation. In studies lasting 30 days, 50 microL of 0.5% UTP was applied 6 times a day for 4 weeks. Tear samples were collected from the conjunctival sac with a glass microcapillary. The protein profile of the tear fluid was analyzed by SDS-polyacrylamide gel electrophoresis and total protein was measured with the Bradford assay. The Easy-Titer rabbit IgG assay kit was used for the determination of immunoglobulin G (IgG). RESULTS:UTP had dose-dependent stimulatory effects on tear secretion. It maximally increased tear secretion about 4-fold 15 min after its application. Similar effects were obtained with ATP. Repeated treatment with UTP reproducibly increased tear volume. Furthermore, UTP did not decrease total protein and IgG concentration in tear fluid and it had no effect on the protein profile. CONCLUSION: These data indicate that activation of P2Y(2) receptor increases tear fluid secretion accompanied with some proteins in normal rabbits. The purinergic agonists, UTP and ATP, have potential therapeutic value in the treatment of dry eye.
Authors: John L Ubels; Ilene K Gipson; Sandra J Spurr-Michaud; Ann S Tisdale; Rachel E Van Dyken; Mark P Hatton Journal: Invest Ophthalmol Vis Sci Date: 2012-10-01 Impact factor: 4.799
Authors: Dongfang Yu; William R Thelin; Troy D Rogers; M Jackson Stutts; Scott H Randell; Barbara R Grubb; Richard C Boucher Journal: Am J Physiol Cell Physiol Date: 2012-07-18 Impact factor: 4.249
Authors: Ki Cheol Chang; Joo Youn Oh; Youn Seok In; Mee Kum Kim; Ki Cheul Shin; Won Ryang Wee; Jin Hak Lee; Myung Gyu Park Journal: J Korean Med Sci Date: 2009-07-30 Impact factor: 2.153