ascorbic-acid and Tympanic-Membrane-Perforation

In this study, we investigated the effect of environmental pH on healing of acute rat tympanic membrane perforations. Twenty Wistar albino rats were divided into four groups and used in the study. A large myringotomy was performed in the posteroinferior quadrants of both tympanic membranes. In left ears, topical pH 4 standard calibration solution was used in groups 1 and 3, and pH 7 standard calibration solution was used in groups 2 and 4. Right ears served as controls, and allowed for spontaneous healing. The solutions were applied for 2 days in groups 1 and 2, and for 7 days in groups 3 and 4. Healing was assessed by macroscopic closure of the tympanic membrane perforation, and histopathological analysis of lamina propria edema, neovascularization, inflammatory cells, and fibroblastic reaction in the temporal bones. pH 7 and pH 4 groups were similar for macroscopic closure of perforation on day 2; however difference was significant on day 7. The fibroblastic activity was significantly less on days 2 and 7 in pH 4 group. On day 7, there were significant differences between pH 4 and pH 7, and pH 7 and control groups for inflammatory cell infiltration. In conclusion, clinical and histopathological results of this study indicated that acidic environmental pH speeded up and shortened wound-healing process. By building up optimum environmental pH, a healthy healing may be achieved in acute tympanic membrane perforations.

Topics: Animals; Antioxidants; Ascorbic Acid; Cell Movement; Epithelial Cells; Fibroblasts; Hydrochloric Acid; Hydrogen-Ion Concentration; Male; Mucous Membrane; Phosphates; Potassium Compounds; Rats, Wistar; Sodium Hydroxide; Tympanic Membrane Perforation; Wound Healing

In the present study, tympanic membranes (TM) harvested from myringotomized rats were analyzed histopathologically to compare the systemic and local effects of ascorbic acid on the development of myringosclerosis.. Forty male Wistar-Albino rats weighing between 350-400 g were included in this study. Under otomicroscopic examination, a standard 2-mm myringotomy incision was made on the posteroinferior quadrant of the TM of both ears. Rats were randomized into five groups as control, topical ascorbic acid 50 mg/kg, systemic ascorbic acid 50, 100, and 200 mg/kg groups, each group containing eight rats. On the 15th day of the study, the rats were decapitated, and bullas of the rats were extracted. Sections were stained with hematoxylin-eosin and examined through light microscopy. Inflammation, distribution width of plaques, edema, and neovascularization were observed on the lamina propria. Thickness of the TM was evaluated under the microscope and scored semiquantitatively.. When intergroup comparisons of parameters related to total TM thickness were performed, differences between the control group and topical AA (ascorbic acid) or systemic treatment groups were found to be statistically significant (p<0.005). A statistically significant difference was detected among control, topical and systemic 200 mg/kg ascorbic acid groups for the edematous lamina propria (p=0.003 and p<0.05, respectively).. For the total TM thickness, systemic and topical ascorbic acid use was effective when compared with the control group. It has been concluded that systemic use of higher doses of (200 mg/kg) ascorbic acid is beneficial in the resolution of the edematous lamina propria.

Topics: Administration, Topical; Animals; Antioxidants; Ascorbic Acid; Disease Models, Animal; Dose-Response Relationship, Drug; Injections, Intraperitoneal; Male; Myringosclerosis; Rats; Rats, Wistar; Tympanic Membrane; Tympanic Membrane Perforation; Wounds and Injuries

We investigated the effect of topical administration of ascorbic acid on the healing process of tympanic membrane perforations in rats.. Thermal myringotomy was induced in both ears of 22 albino rats. The right and left ears were assigned to topical applications of ascorbic acid and saline solution, respectively. The same procedure was performed after 48 hours. Perforations were examined daily by otomicroscopy and healing periods were determined. For histopathologic examination, a single rat in which closure of the tympanic membranes was not completed was sacrificed on days 5, 7, 10, and 12. Data were analyzed with the use of the Student's t-test.. The mean durations of healing in the right and left ears were 7.6 and 8.3 days, respectively. No significant differences were found between the applications of ascorbic acid and saline solution with regard to the duration of closure and histopathologic healing criteria.. Our data suggest that topical application of ascorbic acid have no beneficial effect on the healing of rat tympanic membrane perforations.

Topics: Administration, Cutaneous; Animals; Antioxidants; Ascorbic Acid; Disease Models, Animal; Female; Random Allocation; Rats; Tympanic Membrane Perforation; Wound Healing

Myringosclerosis, a common finding after myringotomy, has been recently associated with an increased production of oxygen free radicals. Ascorbic acid's proposed actions include collagen synthesis, antioxidation, and free radical scavenging. The effects of topical ascorbic acid on healing tympanic membranes were studied. Particular attention was given to detecting the presence of myringosclerosis. Twelve Sprague-Dawley rats were bilaterally myringotomized. Their ears were randomized into group A, which received topical ascorbic acid in Gelfoam, group B, which received topical saline solution in Gelfoam, and group C, which received no treatment. The tympanic membranes were harvested on day 13, after routine otomicroscopy. Under light microscopy, the connective tissue layer of the untouched side of the pars tensa was distinctly thicker in group A than in group B or group C. At this level, the extent of sclerotic lesions was significantly less in the ascorbic acid-treated group. It is inferred that topical ascorbic acid reduces the occurrence of myringosclerosis following tympanic membrane perforations in the rat.

Topics: Administration, Topical; Animals; Ascorbic Acid; Free Radical Scavengers; Male; Middle Ear Ventilation; Rats; Rats, Sprague-Dawley; Sclerosis; Tympanic Membrane; Tympanic Membrane Perforation; Wound Healing