The preventive effects of atorvastatin and N-acetyl cysteine in experimentally induced ischemia-reperfusion injury in rats

AIM

We investigated the effects of atorvastatin and N-acetyl cysteine in decreasing ischemia-reperfusion damage after detorsion of a volvulus of the cecum and ascending colon.

METHODS

Wistar albino rats (250-300 g) were divided into four groups. A cecal-ascending colon volvulus was created by the intestinal clockwise 720° rotation. At the end of one hour, the bowel was detorsioned. Group I (n = 7) was the sham (laparotomy) group, Group II (n = 7) the control (no treatment, volvulus or detorsion), Group III (n = 7) (N-acetyl cysteine administered ) , and Group IV (n = 7) (atorvastatin administered ) group. Blood samples were collected from each group via peripheral veins and centrifuged one hour after detorsion. The parameters of ischemia including malondialdehyde, glutathione peroxidase, catalase, and superoxide dismutase were then observed in the serous fluid.

RESULTS

Malondialdehyde and superoxide dismutase increased in the control group, whereas they were reduced in the Group III and Group IV (p = 0.005; p = 0.008, respectively). The glutathione peroxidase levels revealed no significant differences (p > 0.05), whereas the catalase levels of the group III was higher than in each of the other three groups (p < 0.001). Histopathological evaluation detected reduced lesioning of the organ in the groups which were given atorvastatin and N-acetyl cysteine.

CONCLUSION

Atorvastatin and of N-acetyl cysteine have a similar preventive effect in experimental ischemia-reperfusion injury (Tab. 8, Fig. 6, Ref. 24).

Growth factor and receptor mRNA expression in the intestine of horses with large colon volvulus: a pilot study

REASONS FOR PERFORMING STUDY

Growth factors (GF) are important for maintenance and repair of intestinal mucosal structure and function, but there have been no studies investigating growth factor (GF) or growth factor receptor (GF-R) mRNA expression in the intestine of horses with large colon volvulus (LCV).

OBJECTIVES

(1) To determine mRNA expression for epidermal growth factor (EGF), EGF receptor (EGF-R), insulin-like growth factor-I (IGF), IGF receptor (IGF-R), vascular endothelial growth factor (VEGF) and VEGF receptor (VEGF-R) in the intestine of horses with an LCV compared to normal intestine. (2) To measure the correlation between histological intestinal injury and mRNA expression.

METHODS

In 5 horses, samples were collected from the mid-jejunum (small intestine, SI), pelvic flexure (PF) and right dorsal colon (RDC) prior to creation of the LCV (NORM), 1 h following creation of the LCV (ISCH) and 1 h following correction of the LCV (REPER). In 2 clinical cases of LCV, samples were collected from the PF and RDC. Samples were assessed histologically for the amount of intestinal injury. The mRNA expressions of growth factors and receptors were determined using qRT-PCR.

RESULTS

VEGF and VEGF-R mRNA expression was greater in horses with an LCV compared to NORM. Expression of IGF-R mRNA increased in the SI during ISCH and REPER.

CONCLUSION AND POTENTIAL RELEVANCE

The increase compared to NORM in VEGF and VEGF-R mRNA expression in horses with LCV may be important in early intestinal healing and may also explain, in part, the increase in vascular permeability in horses with a LCV. Expression of IGF and IGF-R in the SI warrants further investigation and may be important for understanding post operative complications in horses with SI lesions.

Detection and comparison of nitric oxide in clinically healthy horses and those with naturally acquired strangulating large colon volvulus

The objective of the study was to determine whether nitric oxide (NO) is present in clinically healthy horses (control) under basal conditions, and if it increases secondary to naturally acquired strangulating large colon volvulus (affected). Eleven affected horses and 10 controls were studied. Jugular venous blood, abdominal fluid, and urine were collected. The NO concentrations were standardized to the creatinine concentration in the respective samples. A biopsy specimen collected from the large colon pelvic flexure at surgery was divided into subsections for processing for inducible nitric synthase (iNOS) and nitrotyrosine (NT) immunohistochemical staining and reduced nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase histochemical staining. There were no significant differences in plasma, abdominal fluid, or urine NO concentrations between affected and control horses. There was a significant decrease in submucosal arteriolar and venular endothelium, submucosal plexus, mucosal leukocyte, mucosal and musclaris vasculature, and myenteric plexus NADPH diaphorase staining in affected versus control horses. There was a significant increase in iNOS staining in mucosal leukocytes and vasculature in affected versus control horses. Other than a greater number of positively stained mucosal leukocytes in affected horses, there were no significant differences between affected and control horses for NT staining. The presence of NADPH diaphorase staining in the endothelium and submucosal neurons suggests endothelial and neuronal NOS are present under basal conditions in the large colon of horses. Increased iNOS and NT staining in mucosal leukocytes of affected horses suggests involvement of the NO pathway in large colon volvulus. The reasons for the lack of a significant difference in plasma, abdominal fluid, and urine NO concentrations between affected and control horses are unknown.