Esophageal Burn In Rats Research Articles

The effects of hesperidin on stricture formation in corrosive esophageal burns: an experimental study

Esophageal strictures in children that develop as a result of accidental ingestion of corrosive substances remain an important health problem. The purpose of this study is to determine the effects of Hesperidin, an effective bioflavonoid in the proliferative and exudative phase of inflammation, on the stricture formation in corrosive esophageal burns. Experimental esophageal burns in rats were created using a modified Gehanno and Guedon model with 20% NaOH. Rats were divided into 5 groups. In the Sham group, the distal esophagus was prepared and cannulated according to the model, but no NaOH was administrated. The esophageal burn was created with NaOH in the other groups. The burned groups were divided into two groups as untreated (T14, T21) and treated with 100mg/kg/day Hesperidin (H14, H21) intraperitoneally, and these groups were divided into two according to their sacrification periods (14 and 21days). Inflammation, fibrosis, and necrosis were graded by histopathological evaluation in all groups. The efficacy of treatment was evaluated using the weight of rats, stenosis index, and histopathological parameters. Histopathologic damage scores such as inflammation, necrosis, and fibrosis were lower in the H14 and H21 groups and higher in the T14 and T21 groups. And also stenosis index was found higher in T14 and T21 groups (p < 0.05), while it was similar to the Sham group in H14 and H21 groups. No statistically significant difference was found between the H14 and H21 groups in terms of stenosis index. When weights of the rats at the beginning and end of the experiment were compared, weights of the H14 and H21 groups and the Sham group were similar. There was a significant decrease in the weight of the rats in the T14 and T21 groups (p < 0.001). This study is the first to use Hesperidin in preventing esophageal damage in an esophageal caustic burn model. It was shown that Hesperidin was effective in reducing macroscopic and microscopic histopathologic damage in the corrosive esophageal burn model, preventing the stricture formation, and has positive effects on nutrition in rats with an esophageal burn.

Protective Effects of Contractubex® on Stricture Formation after Experimental Corrosive Esophageal Burns in Rats

Although many agents have been tested as treatment options for caustic esophageal burn (CEB), none have successfully suppressed the formation of strictures. Thus,the purpose of this study was to determine the efficacy of Contractubex® gel (10% onion extract, 50 U/gr heparin, and 1% allantoin) in stricture preventing after CEB. In this study, 24 Wistar-albino rats were divided into 4 groups. CEB was initiated with an instillation of 1mL of 10% NaOH solution into the an isolated esophageal segment for 3min. Group C (control) was uninjured and untreated. In Group CEB, was initiated but no treatment was given. In Groups CTX1 and CTX2, the animals received 100 and 200mg/kg/d, respectively, of Contractubex® for 4weeks via gavage after CEB was initiated. The stenosis indices (SI), histopathologic damage scores, tissue hydroxyproline (HP) levels, and weights of the rats were taken before the experiment and 4weeks after the experiment. The Mean SI levels, HP levels, and histopathologic damage scores were statistically lower in Groups CTX1 and CTX2 when compared with Group CEB (p <0.05). The treatment groups increased in weight when compared to Group CEB. The results were similar between Group CTX1 and Group CTX2 (p >0,05); the efficacy of the treatment was not dose-dependent. For the first time, Contractubex® was used for its antifibrotic, antioxidant, anti-inflammatory, and wound healing effects to treat caustic esophageal burn in rats. It was effective in reducing stricture formation by decreasing the HP levels and histopathologic damage as well as preventing stenosis and weight gain in the treatment groups.

Effect of polaprezinc on experimental corrosive esophageal burns in rats.

Unconsciously caustic ingestion is one of the most common causes of serious esophageal strictures in children. The aim of this study is to determine the efficiency of polaprezinc in preventing stricture formation after corrosive esophageal burns (CEB); this was the first time it has been used to treat experimental CEB in rats. Twenty-four rats were divided into four groups, three of which received CEB by the instillation of 1 mL of 10% NaOH solution into their isolated esophageal segments for three minutes. Group C (control) was uninjured and untreated. Group B (esophageal burn) received CEB but were left untreated. Groups PT1 and PT2 had CEB and received 100 mg/kg/day and 200 mg/kg/day, respectively, of intraperitoneal polaprezinc treatment (PT) for the first two weeks, then oral PT for another two weeks. We assessed the treatment's efficiency of the treatment after the fourth week by evaluating the stenosis index (SI) and the histopathological damage score, determining tissue hydroxyproline content (HP), and measuring the weight of the rats before and after the experiment. Mean SI was statistically lower in the groups PT1 and PT2 when compared with Group B (p =0.006, 0.004, respectively). HP levels were highest in Group B, but it was insignificant (P>0.05). In terms of histopathological damage score, treatment groups demonstrated less collagen deposition, mucosal, and submucosal damage than both Group B (p =0.01) and Group C (p =0.02). Group PT1 and Group PT2 (P>0.05) showed similar results, indicating the treatment's effectiveness was independent of dosage. Outside of Group C, weight gain was detected only in Group PT2, though it was statistically insignificant. In Group PT1, weight loss was lower than in Group B. Polaprezinc, with its antifibrotic, antioxidant, anti-inflammatory, wound-healing and antiapoptotic effects, was efficient in reducing stricture formation by decreasing HP levels and histopathologic damage, preventing stenosis, and weight gain in higher dosages in the treatment group.

Beneficial Effects of Methylene Blue on the Acute Phase of Corrosive Esophageal Burn in Rats

The aim of the article is to investigate the beneficial effects of methylene blue (MB) on the acute phase of experimental corrosive esophageal burns. A total of 21 male Sprague-Dawley rats were allocated into three groups with an equal number in each group. In Group 1 (control), the esophageal lumen was irrigated with saline. In Groups 2 (untreated) and 3 (MB treatment), the distal esophagus was burned with 30% NaOH solution. In Group 3, MB was applied locally on the distal esophageal lumen (30 mg/kg) 90 minutes after the burn. In all the groups, animals were humanely killed at the end of the 7th day. Distal esophageal specimens were obtained for histopathological and biochemical examinations. MB increased the tissue superoxide dismutase levels and the total antioxidant status, whereas it decreased the levels of the total oxidant status with significant attenuation of histopathological damage. MB might have reduced the tissue damage in corrosive esophagitis because of its antioxidant effects.

Protective Effect of Dimethyl Sulfoxide on Stricture Formation in Corrosive Esophageal Burns in Rats

The aim of this study was to investigate the effects of dimethyl sulfoxide (DMSO) on stricture formation in corrosive esophageal burns. A total of 21 male rats were divided equally into three groups. In Group 1 (burn) and Group 2 (burn + DMSO) burns were induced in the distal esophagi with a 30% NaOH solution. In Group 3 (control), a saline solution was applied to the esophageal lumen. In Group 2, DMSO was administered intraperitoneally (3 mg/kg) 15 minutes after the burn was induced and then every 24 hours for 7 days. All rats were humanely killed at the end of Day 22. Distal esophagi were harvested for analysis. The stenosis index (SI) and histopathologic damage score were evaluated in addition to malondialdehyde (MDA), myeloperoxidase (MPO), nitric oxide (NO), tumor necrosis factor alpha (TNF-α), and interleukin-6 (IL-6) levels. DMSO significantly decreased the levels of MDA, NO, TNF-α, and IL-6 in the rats with burned esophagi. Furthermore, the SI and histopathologic scores decreased significantly in the burn + DMSO group relative to the burn group (p < 0.05). Our results suggest that DMSO can decrease the occurrence of stricture formation and could represent a beneficial alternative therapy for the treatment of corrosive esophagitis.

Preliminary study of efficacy of hyaluronic acid on caustic esophageal burns in an experimental rat model

BackgroundThe aim of this study was to investigate the effectiveness of hyaluronic acid on the prevention of esophageal damage and stricture formation after experimental caustic (alkaline) esophageal injury in rats. Materials and MethodsTwenty-one Wistar albino rats were randomly divided into three groups. A caustic esophageal burn was created following the Gehanno model: Group l (n=7) underwent operation, but no injury; Group 2 (n=7) was injured and left untreated; and Group 3 (n=7) was injured and treated with hyaluronic acid, first topically and then orally by gavage (2×0.3mL; 12.5mg/mL for 7days). The caustic esophageal burn was created by instilling 25% NaOH into the distal esophagus. All rats were euthanized on day 22 for evaluation. The efficacy of hyaluronic acid treatment was assessed histopathologically and biochemically via blood determination of the total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), and sulfhydryl group (SH) and lipid hydroperoxidase (LOOH) levels. Statistical analyses were performed. ResultsWeight gain was significantly lower in Group 2 than in the other two groups (P<0.05). The mean stenosis index, histopathologic damage score, TAS, TOS, OSI, and SH and LOOH levels were higher in Group 2 than in the other two groups. The mean stenosis index, inflammation, TAS, SH and OSI in Group 2 were significantly different than those in the other two groups (P<0.05). ConclusionHyaluronic acid treatment is effective in treating damage and preventing strictures after caustic esophageal burn in rats.

A novel model approach for esophageal burns in rats

Corrosive esophageal injury causes serious clinical problems. We aimed to create a new experimental esophageal burn model using a single catheter without a surgical procedure. We conducted the study with two groups of 12 male rats that fasted for 12h before application. A modified Foley balloon catheter was inserted into the esophageal lumen. The control group was given 0.9% sodium chloride, while the experimental group was given 37.5% sodium hydroxide with the other part of the catheter. After 60s, esophagus was washed with distilled water. The killed rats were examined using histopathological methods after 28days. In comparison with the histopathological changes experienced by the study groups, the control groups were observed to have no pathological changes. Basal cell degeneration, dermal edema, and a slight increase in the keratin layer and collagen density of submucosa due to stenosis were all observed in the group subjected to esophageal corrosion. A new burn model can thus, we believe, be created without the involvement of invasive laparoscopic surgery and general anesthesia. The burn in our experiment was formed in both the distal and proximal esophagus, as in other models; it can also be formed optionally in the entire esophagus.

Effect of Stent Placement, Balloon or Cutting Balloon Dilatation on Stricture Formation after Caustic Esophageal Burn in Rats

This study aimed to evaluate the effects of stent placement prior to stricture development following caustic esophageal burn (CEB) in an animal model. The outcomes after stent placement were also compared with those after balloon dilatation and cutting balloon dilatation performed after stricture development. Groups were compared with regard to stricture development and weight loss. 40 rats were divided into 5 groups. CEB was created as described by Gehanno etal. In Group A (control) no CEB was performed and the esophagus was only rinsed with saline. Group B rats underwent CEB with no subsequent treatment. Group C rats underwent CEB followed by balloon dilatation in the 3 (rd) and 4 (th) week. Group D rats underwent CEB followed by cutting balloon dilatation in the 3 (rd) week. Group E rats underwent CEB with subsequent placement of a silicon stent in the same session. The animals were sacrificed in the 6 (th) week, and the stenosis index (SI), collagen deposition, and hydroxyproline (HP) levels were determined in the esophageal segments and statistically compared. Although weight loss occurred in Group C and Group B rats (238.87±15.95 g vs. 233.83±19.01 g), weight loss in Group C rats was less marked compared to Group B. Similarly, the SI in Group C was lower compared to that of Group B and the difference was statistically significant. Although there was no difference in weight between the rats in Group C and Group B before the procedure (p=0.318), there was statistically significant difference thereafter (p=0.002). The SI of Group D was also lower compared with that of Group B, and the difference was statistically significant. Weight gain in Group E rats was similar to that noted in Group A rats and was higher compared to Group B; this difference was statistically significant. The SI for Group E was lower compared to that of Group B. Stenting performed at the time of corrosive injury and cutting balloon dilatation performed after stricture formation had a positive effect with regard to SI and weight gain in an animal model.

Effects of retinoic acid and zinc on the treatment of caustic esophageal burns

An experimental study was carried out to investigate the efficacy of an anti-inflammatory and antiproliferative agent all-trans retinoic acid (ATRA) and an antioxidant agent zinc sulphate (ZnSO(4)) in the prevention of stricture after caustic esophageal burn in rats. Esophageal burn was induced using 50% NaOH. Rats were divided into four groups as follows: group A (sham; n = 8), group B (control; n = 8), group C (treated with ATRA; n = 8) and group D (treated with ZnSO(4); n = 8). All rats were killed on the 28th day and esophageal tissues were evaluated for histopathologic damage score, hydroxyproline (HP) content and TGF-beta1 expression. Significant difference was detected in terms of histopathologic damage score between groups B and C (p = 0.002). Although mean HP levels of groups C and D were lower than group B, statistical comparison was not significant. TGF-beta1 expression in group C was significantly lower than group B. Zinc has not been found effective in the prevention of stricture formation. The results indicate that ATRA has a preventive effect in the development of fibrosis in an experimental model of caustic esophageal burns in rats.

Mitomycin C decreases the rate of stricture formation in caustic esophageal burns in rats

Although the incidence of caustic ingestion is declining, the management of caustic esophageal strictures remains a challenge. Although many agents have been tried experimentally to treat strictures, few have gained clinical application. The aim of this study was to investigate the influence of mitomycin C (MMC), which inhibits fibroblastic proliferation in treating delayed caustic esophageal strictures. Forty-two rats were allocated into 3 groups. Caustic esophageal burns were created as described by Gehanno. Group A was instilled only with saline. Group B was injured with 10% NaOH and left untreated. Group C was injured and received topical MMC at 0.04% concentration in the fourth week. At 56 days, stenosis index (SI), collagen deposition, and hydroxyproline content (HP) were determined in distal esophageal segments. Statistical analyses were performed. The mean SI in group B was significantly higher than others (SI: 1.15 +/- 0.37 d/lum, P < .05). Collagen accumulation was highest in group B, followed by groups C and A, respectively. Collagen deposition in group C was statistically lower than group B (P < .018). The mean HP in group B was statistically higher than others (5.07 +/- 1.30 microg/mg tissue, P < .05), and similar between groups A and C (1.20 +/- 0.20, 1.91+/- 0.79, respectively, P = .73). In the current study, MMC treatment ameliorated caustic esophageal stricture as reflected in the significantly lower SI. We conclude that MMC application is effective in the treatment of caustic esophageal strictures.

Role of caffeic acid phenethyl ester, an active component of propolis, against NAOH-induced esophageal burns in rats

This study was evaluated to investigate the efficacy of caffeic acid phenethyl ester (CAPE), which is a natural honeybee product exhibits a spectrum of biological activities including anti-microbial, anti-inflammatory, antioxidant and anti-tumoral actions, on the prevention of stricture development after esophageal caustic injuries in the rat. Thirty healthy male Wistar albino rats were utilized in this study. The rats were randomly allotted into one of three experimental groups: group A (sham) animals were uninjured. Caustic esophageal burn was created by applying 1 ml 37.5% NaOH to the distal esophagus. Group B rats were injured but untreated. Group C rats were injured and received CAPE (10 micromol/kg/day i.p. for 28 days). Efficacy of the treatment was assessed by measuring the esophageal transit time, stenosis index, histopathologic damage score and biochemically by determining tissue hydroxyproline content, lipid peroxidation and antioxidant enzyme activities. The esophageal transit time, the stenosis index, histopathologic damage score and the hydroxyproline level were significantly increased in the untreated group compared with the sham and CAPE-treated groups. Treatment with CAPE decreased tissue hydroxyproline levels, histological damage, and the stenosis index, but except the esophageal transit time. Caustic esophageal burn also increased the lipid peroxidation and decreased the antioxidant enzyme activities in the untreated group. CAPE treatments decreased the elevated lipid peroxidation and also increased the reduced antioxidant enzyme activities. In corrosive esophageal burn group with no treatment, the most consistent findings were degenerative changes and increased in submucosal collagen content, and the luminal narrowing. CAPE treatment protected esophagus. Nevertheless, there was the slight increase in submucosal collagen. It is concluded that CAPE has a preventive effect on the stricture development after esophageal caustic injuries in the rat.

Colchicine in experimental alkaline burns of the rat esophagus: an old drug, a new indication?

An experimental study was performed to investigate the efficacy of colchicine in the prevention of fibrosis in the alkaline burn of the esophagus in rats. A standard esophageal alkaline burn was produced by the application of 37.5% NaOH for a period of 90 s to the distal esophagus followed by a water rinse. The experiments were conducted twice with two different dosages of colchicine. In the first experiment, colchicine 1 mg/kg (i.p.) was applied once, on the first day. Group A (n:8), the sham laparotomy group; group B (n:8), the untreated group (positive control group); Group C (n:16), where the standard esophageal burn was induced and colchicine applied at a dose of 1 mg/kg i.p. in 1 ml volume, and group D (n:14), where the rats did not have any operation, but were treated with colchicine (1 mg/kg, i.p.) as in group C. In the second experiment, colchicine was applied at repeated doses of 100 microg/kg (i.p.) on the first, 7th, 14th, and 21st days. Twenty-five rats were divided into groups. Group AA (n:8), the sham laparotomy group; group BB (n:9), the untreated group (positive control group); and group CC (n:8), where the standard esophageal burn was induced and colchicine was applied at repeated doses. All the rats were killed on the 28th day and evaluated for esophageal tissue hydroxyproline content and histopathologic damage score. Colchicine treatment at a dose of 1 mg/kg significantly reduced the quantity of hydroxyproline in the esophageal tissue in groups C and D compared with the positive control group B (P < 0.05). However, it is associated with a mortality rate of 60%. Colchicine at repeated doses of 100 microg/kg showed no significant effect in group CC compared to the untreated group BB and in the quantity tissue of hydroxyproline content (P > 0.05). At non-toxic doses, colchicine was not effective in the treatment of alkaline esophageal burn in rats. Colchicine-like molecules with less adverse effects or colchicine itself in titrated doses may be hopeful in preventing the development of fibrosis in the alkaline burns of the esophagus.

Effect of the prostacyclin derivate iloprost in experimental caustic esophageal burn

Previous experimental studies have suggested that administration of antithrombotic, antioxidant, and cytoprotective agents have protective effects in caustic injury of the esophagus. Therefore, an experimental study was carried out to investigate the effects of iloprost, a stable analogue of prostacyclin, on the esophagus after caustic burns. Sixty Wistar albino rats were divided into three groups of 20 animals each. In group A, animals were uninjured and untreated. In group B, animals were injured but untreated. In group C, rats were injured and administered intravenous iloprost for 3 days. Caustic esophageal burn was produced by 1 ml of 15% NaOH. Efficacy of the treatment was assessed by measuring the tissue malondialdehyde (MDA), superoxide dismutase, and glutathione levels with biochemical methods on the 3rd postoperative day. Histopathological evaluation was done on the 28th postoperative day. The level of MDA was significantly increased in group B compared with the other groups. In group B, the histopathological damage score was significantly higher than in groups A and C. There was also a significant difference between groups A and C regarding the histopathologic damage. These results indicate that iloprost has a preventive effect in experimental caustic esophageal burn in rats.

Trapidil, an Inhibitor for Phosphodiesterase and Platelet-Derived-Growth Factor, Ameliorates Corrosive Esophageal Burn in Rats

Corrosive esophageal burn is a common health problem in the pediatric age group and causes serious esophageal injuries. The medical treatment in acute phase of corrosive esophageal injury is of particular importance for prevention of esophageal stricture. We therefore aimed to investigate the possible beneficial effect of trapidil (triazolopyrimidine), an inhibitor for phosphodiesterase and platelet-derived-growth-factor, during acute phase of esophageal corrosive injury. Wistar albino rats were randomly allocated to untreated, treated, and sham-operated groups (n = 10 for each group). Corrosive esophageal burn was generated with 10% NaOH solution. The rats were left untreated (untreated group) or treated with trapidil as a single dose of 40 mg/kg intraperitoneally after one hour of the injury (treated group). Abdominal esophageal segment was isolated and tied in sham-control group. The studied esophageal segment was removed from each animal after 24 hours. Malondialdehyde (MDA) and nitric oxide (NO) levels were measured in the esophageal tissues. The ulcer depth was graded by histopathologic examination. MDA and NO levels were significantly higher in the untreated group than in the treated group. Namely, trapidil treatment significantly decreased MDA and NO levels in the injured tissues, the levels of which are similar to those in the tissues of control animals. The grades of ulcer depth were significantly improved in the treated group. These results indicate that the reactive oxygen radicals increase in the early phase of corrosive esophagitis and cause tissue damage. We suggest that trapidil treatment may be useful in acute phase of corrosive esophageal injury.

Mitomycin C prevents strictures in caustic esophageal burns in rats

Caustic esophageal injuries lead to stricture formation. Although a number of agents have been tried experimentally to prevent strictures, few have gained clinical application. The purpose of this study was to investigate the effectiveness of Mitomycin C (MMC), which inhibits fibroblastic proliferation in preventing caustic esophageal strictures. Fifty-six rats were allocated into four groups. Caustic esophageal burns were created as described by Gehanno. Group A was instilled only with saline. Group B was injured and untreated. Groups C and D were injured and received topical MMC at 0.02 and 0.04% concentrations, respectively. At 28 days, stenosis index (SI), collagen deposition, and hydroxyproline content (HP) were determined in distal esophageal segments. Statistical analyses were done. Mean SI in Group B was significantly higher than others (P < 0.05). Mean SI was statistically higher in Group C than A and D and similar between groups A and D. The greatest accumulation of collagen was found in Group B, followed by Group C, D, and A, respectively. Collagen deposition in Group D was statistically lower than Group B (P < 0.01) and similar to Group C. Mean HP in Group B was statistically higher than others (P < 0.05), significantly higher in Group C than Group D (P = 0.047), and similar between Groups A and D (P = 0.73). MMC was effective in preventing strictures following experimental caustic esophageal injury, in a dose-dependent manner. We consider that it can gain clinical utilization with the establishment of effective mode, dose, and timing of therapy.

Mitomycin C prevents strictures in caustic esophageal burns in rats

<h3>Background</h3> Caustic esophageal injuries lead to stricture formation. Although a number of agents have been tried experimentally to prevent strictures, few have gained clinical application. The purpose of this study was to investigate the effectiveness of Mitomycin C (MMC), which inhibits fibroblastic proliferation in preventing caustic esophageal strictures. <h3>Material and methods</h3> Fifty-six rats were allocated into four groups. Caustic esophageal burns were created as described by Gehanno. Group A was instilled only with saline. Group B was injured and untreated. Groups C and D were injured and received topical MMC at 0.02 and 0.04% concentrations, respectively. At 28 days, stenosis index (SI), collagen deposition, and hydroxyproline content (HP) were determined in distal esophageal segments. Statistical analyses were done. <h3>Results</h3> Mean SI in Group B was significantly higher than others (<i>P</i> < 0.05). Mean SI was statistically higher in Group C than A and D and similar between groups A and D. The greatest accumulation of collagen was found in Group B, followed by Group C, D, and A, respectively. Collagen deposition in Group D was statistically lower than Group B (<i>P</i> < 0.01) and similar to Group C. Mean HP in Group B was statistically higher than others (<i>P</i> < 0.05), significantly higher in Group C than Group D (<i>P</i> = 0.047), and similar between Groups A and D (<i>P</i> = 0.73). <h3>Conclusion</h3> MMC was effective in preventing strictures following experimental caustic esophageal injury, in a dose-dependent manner. We consider that it can gain clinical utilization with the establishment of effective mode, dose, and timing of therapy.

Effects of hyperbaric oxygen therapy on caustic esophageal injury in rats

Background/purpose Caustic esophageal burn is a serious problem in pediatric surgery. Even though many clinical and experimental studies had been performed, the complication rate could not be reduced to a satisfying level. In this study, the authors evaluated the effects of hyperbaric oxygen (HBO) therapy in caustic esophageal burn in rats. Methods Rats were divided into 4 groups, and caustic burn at the distal esophagus was created by applying 50% NaOH for 3 minutes in all groups. The first and third groups did not receive HBO therapy. HBO therapy was applied to the second group for 2 days and to the fourth group for 28 days. To evaluate the effects of short-term HBO therapy, the first 2 groups were compared for ulceration, inflammation, and submucosal vascular thrombosis after 2 days. The third and fourth groups were compared for the long-term effects of HBO therapy. Rats in these groups were killed after 28 days and compared for the collagen content, weight, and mortality rate. Results In the second group, which received 2 days of HBO therapy, ulcer depth and vascular thrombosis were significantly lower than these in the first group ( P = .022 and P = .020, respectively). The fourth group, which received 4 weeks of HBO therapy, had a significantly reduced mortality rate, weight loss, and collagen score and hydroxyproline level if compared with the third group ( P = .035; P = .016; P = .028; and P = .033, respectively). Conclusions These results indicate that HBO therapy is useful in caustic esophageal burn both in short-term and long-term use.

Polyunsaturated phosphatidylcholine lowers collagen deposition in a rat model of corrosive esophageal burn.

Esophageal strictures are characterized by excess deposition of collagen in the esophageal wall. Polyunsaturated phosphatidyl-choline (PPC) stimulates collagen breakdown in experimental models of liver cirrhosis and colitis. This study was done in order to investigate the therapeutical effect of PPC in preventing esophageal strictures due to alkali-induced esophageal burns in rats. Fifty-five albino rats were divided into four groups as follows: control group (Group A, 10 rats), rats with sham operation and treated with saline (Group B, 15 rats), rats with esophageal burns only (Group C, 15 rats), and PPC-fed rats with esophageal burns (Group D, 15 rats). A standard esophageal burn was produced as described by Gehanno. PPC was administered orally to Group D rats in doses of 100 mg/day for four weeks. All animals were sacrificed on the 28th day of the experiment. Hydroxyproline levels in esophageal tissue was determined in each rat, and histopathologic evaluation was performed for each group. Hydroxyproline levels were significantly lower in the PPC-fed rats than in the rats with pure esophageal burns (p < 0.001). Histopathologically, collagen deposition in the submucosa and tunica muscularis was lower in Group D rats (PPC-fed rats with esophageal burn) than Group C rats (pure esophageal burn) (p < 0.05). As a result of our study, we concluded that PPC has an ameliorating effect on stricture formation after alkali-induced corrosive esophageal burns in rats.

Effects of estradiol and progesterone on the synthesis of collagen in corrosive esophageal burns in rats

The effects of sex hormones on the synthesis of collagen were investigated in rats with alkali-induced corrosive esophageal burns. In 75 rats, a standard esophageal burn was produced as described by Gehanno. The animals were then grouped as follows: controls (group A), animals with pure esophageal burns (group B), and animals with esophageal burns treated with estradiol and progesterone (group C). All animals were killed on the 28th day of the experiment. Hydroxyproline levels were determined, and histopathologic evaluation was performed for each group. The hydroxyproline levels were significantly lower in the rats treated with estradiol and progesterone. Histopathologically, collagen deposition in the submucosa and tunica muscularis was lower in the estradiol/progesterone group than in the group with pure esophageal burns. Based on the results, the authors believe that estradiol and progesterone inhibited new collagen synthesis, and therefore, alkali-induced esophageal stricture formation.