The role of adenine and guanine in beneficial effects of the gastric pentadecapeptide BPC 157 (PL 14736) on ileoileal anastomosis healing in rats impaired with systemic corticosteroid application. Raman spectroscopy study

Safe in inflammatory bowel disease (PL14736 Pliva, Croatia), no toxicity reported (Gastroenterology, 2005), gastric pentadecapeptide BPC 157 (BPC 157) heals the intestinal anastomosis (Surg Today, 2007). Raman spectroscopy was used to show the beneficial effect of BPC 157 on anastomosis healing in rats impaired with systemic corticosteroid application. Assessed were Raman spectroscopy, ileoileal anastomosis dehiscence, histology, biomechanical presentation (the volume (ml) (infunded through syringe-perfusion pump system (1ml /10 sec)) and the leakage pressure (mmHg) (catheter connected with chamber and monitor, at 10 cm proximal to anastomosis), on days 1, 2, 3, 4, 5 and 6. BPC 157 10µg, 6-alpha-methylprednisolone (MP) 1 mg, given alone or together /kg i.p. (or an equivolume of saline 5ml/kg). First application was after surgery and last was 24 h before sacrifice. Raman spectroscopy. Measurements used Perkin Elmer Spectrum GX FT Raman spectrometer with 4 cm-1 resolution. Excitation was NdYaG laser at 1064 nm wavelength and used laser power was 500 mW. Spectra were recorded in the area between 300 and 2300 cm-1, with 50 scans for better S/N ratio. Prior to mounting on a universal holder, the specimen was cut to a 0.3 x 0.3 cm piece. Presenting almost constant intensity for all investigated samples, all spectra were baseline corrected and normalized to band at 1450 cm-1. Raman spectroscopy. To point out an advanced healing rate the spectral areas from 510 to 560 cm-1, 800 to 1150 cm-1 and band at 1490 cm-1 were individually observed. We focused the band at 1490 cm-1, assigned to vibrations of adenine and guanine, to be indicative for increased tissue regeneration, since it fully correlates with the evidenced healing process. BPC 157 rats showed an increase throughout the 1-6 days following surgery ; MP-rats did not show before day 6. This healing delay is fully counteracted when rats received BPC 157 simultaneously with MP. Macroscopic and histology data support these findings: adhesion formation attenuated, blood vessels filled, mild passage obstruction only temporary ; anastomosis without leakage sustains markedly higher both volume and pressure, with consistent increase to healthy values ; decreased edema, granulocyte number and necrosis, along with granulation tissue, reticulin and collagen formation substantially increased, and finally epithelization increased (BPC 157) ; (MP)causing aggravation. These data signify the role of adenine and guanine in the anastomosis healing process, BPC 157 has a beneficial effect, MP negative effect, and counteracted corticosteroid impairment by BPC 157 application.