Untersuchung des Arginin-Stoffwechsels in Kolon-Anastomosen: temporäre Expression von iNOS und Arginase

Abstract

L-arginine is the substrate for the nitric oxide synthase (NOS) pathway that is essential for gastrointestinal wound healing. L-Arginine is also the Substrate for the enzyme arginase which metabolizes L-arginine to ornithine and urea and subsequently to polyamines and proline both known to interact in cell proliferation and collagen synthesis. The temporal expression of the L-arginine metabolism in colon anastomosis was investigated.

Male rats underwent laparotomy. A left sided colotomy was performed and the colon was then reanastomosed using 6-0 prolene. Sham operation was performed in controls. On day 2, 5, 10, 14 and 28 after the surgery the anastomosis was excised. The tissue at the anastomosis (ANAST) as well as above and below the anastomosis (PDA) and from sham colon was harvested and analyzed for arginase activity, protein and RNA expression. Statistical analysis was performed by student’s t-test, significance was reached when p < 0.05.

Arginase activity, protein and RNA expression were significantly upregulated at the anastomosis compared to sham controls and PDA colons at all time points. iNOS expression was also upregulated at the anastomosis, however, for a shorter time period after wounding.

Arginase activity is significantly increased during anastomotic healing probably by a combination of transcriptional and post-translational mechanism.