Alkalies/therapeutic use* ; Burns, Chemical/drug therapy* ; Corneal Injuries/drug therapy* ; Eye Burns/drug therapy* ; Humans ; Taurine

Metabolic acidosis is a cause of renal disease progression, and alkali therapy ameliorates its progression. However, there are few reports on the role of renal acid-base transporters during alkali therapy. We evaluated the effect of sodium bicarbonate therapy and the role of acid-base transporters on renal disease progression in rats with a remnant kidney. Sprague-Dawley rats consumed dietary sodium bicarbonate (NaHCO3) or sodium chloride (NaCl) with 20% casein after a 5/6 nephrectomy. After being provided with a casein diet, the NaHCO3-treated group had higher levels of serum bicarbonate than the control group. At week 4, the glomerular filtration rate in the NaHCO3 group was higher than that in the NaCl group, and the difference became prominent at week 10. The glomerulosclerosis and tubulointerstitial damage indices in the NaHCO3 group were less severe compared with controls at week 4 and 10. The expression of the Na/H exchanger (NHE) was decreased, and apical reactivity was decreased in the NaHCO3 group, compared with the NaCl group. Endothelin-1 levels in the kidney were also decreased in the NaHCO3 group. Dietary sodium bicarbonate has the effects of ameliorating renal disease progression, which may be related to the altered expression of NHE in the remaining kidney.
Acidosis/*drug therapy ; Alkalies/*therapeutic use ; Animals ; Caseins/administration & dosage ; Disease Progression ; Glomerular Filtration Rate/drug effects ; Glomerulosclerosis, Focal Segmental/drug therapy ; Kidney/injuries ; Male ; Nephrectomy ; Nephritis, Interstitial/drug therapy ; Rats ; Rats, Sprague-Dawley ; Renal Insufficiency/*drug therapy ; Sodium Bicarbonate/*therapeutic use ; Sodium Chloride/administration & dosage ; Sodium-Hydrogen Antiporter/*antagonists & inhibitors

OBJECTIVETo evaluate the efficacy of epigallocatechin gallate (EGCG) in treatment of corneal alkali burn injury in mice.

METHODSCorneal alkali burn injury was induced by sodium hydroxide method in C57BL/6J mice. The mice with cornea burns were treated intraperitoneally with EGCG solution or phosphate buffer solution (PBS) respectively. The healing of corneal epithelium, the formation of corneal neovascularization (CNV) and the inflammation reaction were assessed by slit -lamp microscopy and histological examination. Expression of vascular endothelial growth factor (VEGF) mRNA and protein in cornea was evaluated by real -time reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry, respectively. Myeloperoxidase (MPO) assay was used to quantitatively evaluate the polymorphonuclear neutrophils (PMNs) infiltration in the corneas.

RESULTSThe healing rate of corneal epithelium in EGCG group was significantly higher than that of PBS group at d1, d3 and d7 after treatment (d1: 41.0%±13.0% vs 23.8%±7.6%; d3: 76.6%±7.5% vs 61.2%±6.8%; d7: 87.8%±8.5% vs 74.0%±9.1%; all P <0.05). The CNV scores and the number of CNV in the corneal sections of EGCG group were significantly lower than those of PBS group at d3, d7 and d14 after treatment (CNV score: d3: 1.1±0.5 vs 6.6±1.0; d7: 1.3±0. 3 vs 8.1±1.0; d14: 0.9±0.2 vs 9.2±1.1; CNV number: d3: 1.68±0.61 vs 2.92±0.95; d7: 4.80±1.36 vs 7.92±1.28; d14: 3.64±0.71 vs 5.88±0.76; all P<0.05) . The expression of VEGF protein at d3 (0.19±0.05 vs 0.45±0.08) and d7 (0.42±0.07 vs 0.84±0.09), the expression of VEGF mRNA at d1, d3 and d7 in EGCG group were significantly lower than those in PBS group (all P <0.05). Compared to PBS group, the inflammatory index at d3 (3.2±0.4 vs 3.7±0.5) and d7 (2.3±0.5 vs 4.0±0.0), the number of PMNs in the corneal sections and the MPO values at d3, d7 and d14 in EGCG group were significantly decreased (PMNs: d3: 34.5±15.7 vs 90.0±28.8; d7: 17.1±11.4 vs 54.9±25.9; d14: 12. 8±4.6 vs 39.0±17.9; all P <0.05).

CONCLUSIONIn the murine corneal alkali burn model, intraperitoneal injection of EGCG solution can promote the healing of corneal epithelium, inhibit the formation of CNV and reduce the inflammatory cell infiltration in the corneas.

Alkalies ; Animals ; Burns, Chemical ; drug therapy ; Catechin ; analogs & derivatives ; therapeutic use ; Cornea ; drug effects ; pathology ; Corneal Neovascularization ; prevention & control ; Disease Models, Animal ; Eye Burns ; drug therapy ; Inflammation ; drug therapy ; immunology ; Mice ; Mice, Inbred C57BL ; Neutrophils ; cytology ; RNA, Messenger ; Vascular Endothelial Growth Factor A ; metabolism