RESUMO
The ulcerogenic potential of dopamine antagonists and L-NAME in rats provides unresolved issues of anti-emetic neuroleptic application in both patients and experimental studies. Therefore, in a 1-week study, we examined the pressures within the lower oesophageal and the pyloric sphincters in rats [assessed manometrically (cm H2O)] after dopamine neuroleptics/prokinetics, L-NAME, L-arginine and stable gastric pentadecapeptide BPC 157 were administered alone and/or in combination. Medication (/kg) was given once daily intraperitoneally throughout the 7 days, with the last dose at 24 h before pressure assessment. Given as individual agents to healthy rats, all dopamine antagonists (central [haloperidol (6.25 mg, 16 mg, 25 mg), fluphenazine (5 mg), levomepromazine (50 mg), chlorpromazine (10 mg), quetiapine (10 mg), olanzapine (5 mg), clozapine (100 mg), sulpiride (160 mg), metoclopramide (25 mg)) and peripheral(domperidone (10 mg)], L-NAME (5 mg) and L-arginine (100 mg) decreased the pressure within both sphincters. As a common effect, this decreased pressure was rescued, dose-dependently, by BPC 157 (10 µg, 10 ng) (also note that L-arginine and L-NAME given together antagonized each other's responses). With haloperidol, L-NAME worsened both the lower oesophageal and the pyloric sphincter pressure, while L-arginine ameliorated lower oesophageal sphincter but not pyloric sphincter pressure, and antagonized L-NAME effect. With domperidone, L-arginine originally had no effect, while L-NAME worsened pyloric sphincter pressure. This effect was opposed by L-arginine. All these effects were further reversed towards a stronger beneficial effect, close to normal pressure values, by the addition of BPC 157. In addition, NO level was determined in plasma, sphincters and brain tissue. Thiobarbituric acid reactive substances (TBARS) were also assessed. Haloperidol increased NO levels (in both sphincters, the plasma and brain), consistently producing increased TBARS levels in the plasma, sphincters and brain tissues. These effects were all counteracted by BPC 157 administration. In conclusion, we revealed that BPC 157 counteracts the anti-emetic neuroleptic class side effect of decreased pressure in sphincters and the dopamine/NO-system/BPC 157 relationship.
RESUMO
AIM: Rectovaginal fistula is a devastating condition providing more than 99% of patients for surgical treatment. We hypothesized that rectovaginal fistula may be healed by therapy with stable gastric pentadecapeptide BPC 157, in consistence with its initial clinical application and effect on external fistulas. MAIN METHODS: BPC 157 (10µg/kg or 10ng/kg) was given perorally, in drinking water (0.16µg/ml or 0.16ng/ml, 12ml/rat/day) till sacrifice, or alternatively, intraperitoneally, first application at 30min after surgery, last at 24h before sacrifice. Controls simultaneously received an equivolume of saline (5.0ml/kg ip) or water only (12ml/rat/day). The assessment (i.e., rectal and vaginal defect, fistula leakage, defecation through the fistula, adhesions and intestinal obstruction as healing processes) was at day 1, 3, 5, 7, 10, 14 and 21. KEY FINDINGS: Regularly, rectovaginal fistulas exhibited poor healing, with both of the defects persisting, continuous fistula leakage, defecation through the fistula, advanced adhesion formation and intestinal obstruction. By contrast, BPC 157 given perorally or intraperitoneally, in µg- and ng-regimens rapidly improved the whole presentation, with both rectal and vaginal defects simultaneously ameliorated and eventually healed. The maximal instilled volume was continuously raised till the values of healthy rats were achieved, there were no signs of defecation through the fistula. A counteraction of advanced adhesion formation and intestinal obstruction was achieved. Microscopic improvement was along with macroscopic findings. SIGNIFICANCE: BPC 157 effects appear to be suited to induce a full healing of rectovaginal fistulas in rats.