Design of radiolabeled gelatinase inhibitor peptide ((99m)Tc-CLP) and evaluation in rats.

In malignant tissues, MMP-9 (gelatinase B, 92 kDa type IV collagenase) and MMP-2 (gelatinase A, 72 kDa type IV collagenase) are the most prevalent matrix metalloproteinases related to the tumor aggressiveness and metastatic potential. Since elevated levels of gelatinases are associated with poor prognosis in cancer patients, these enzymes are potential targets for tumor imaging to possibly predict metastases. In the present study, a cyclic decapeptide, CLP (Cys-Leu-Pro-Gly-His-Trp-Gly-Phe-Pro-Ser-Cys), was selected as a basic peptide because of its selective inhibitory activity toward gelatinases. The peptide was labelled with (99m)Tc with a radiolabelling efficiency of 94.6±4.1%. After determining the appropriate conditions for radiolabelling, a biodistribution study of radiolabelled peptide in Albino Wistar rats was done. According to biodistribution data, (99m)Tc-CLP showed high uptake in the lung, liver, uterus and spleen. The amount of normal tissue MMPs enzymes is known to be lower than a tumor tissue. In this connection, our findings show that matrix metalloproteinases inhibitory peptide which is CLP is labeled with (99m)Tc with high yield and radiolabeled peptide might be might be utilized for the imaging of gelatinase activity due to overexpression of MMP-2 and MMP-9 in tumor tissue.

Influence of uracil on bacterial translocation in an intestinal obstruction model in rats.

INTRODUCTION: Bacterial translocation occurs when intestinal mucosa and the intestinal wall lose their barrier properties against bacteria such as in the case of intestinal obstruction. Enteral nutrition with immunonutrients strengthens the immune system and thickens the intestinal barrier thus preventing bacterial translocation. AIM: The purpose of this study is to investigate the effect of uracil which is an immunonutrient on bacterial translocation using rats with intestinal obstruction as a model. METHODS: Wistar albino rats were divided into three groups. The control group was fed with standard chow diet, while the other two groups were fed with uracil-supplemented chow diet. The rats were fed with these diets for seven days. And the end of the feeding period all groups were submitted intestinal obstruction and injected with (99m)Tc labeled Escherichia coli into the rats' terminal ileum under anesthetic. The rats were sacrificed 24 h later. Their blood, mesenteric lymph nodes (MLN), liver, spleen, lung and ileum were removed to determine level of radioactivity. RESULTS: When compared with the control group it was determined that uracil supplementation reduced the level of bacterial translocation. CONCLUSION: Uracil may be used in the prevention of bacterial translocation in cases of intestinal obstruction because it strengthens the intestinal barrier and the immune system. However, more studies are needed to clearly explain the mechanism behind uracil's beneficial role here.