Efeitos da castração pós-natal sobre o tecido pulmonar após sepse experimental de origem abdominal em ratos

Median lethal needle caliber in two models of experimental sepsis

PURPOSE

To estimate the median lethal needle caliber (LC50) of a new experimental sepsis model and compare it to the LC50 of the cecal ligation and puncture (CLP) sepsis model.

METHODS

Male albino Wistar rats were studied (n=22). Animals were allocated into two study groups. In Group I, experimental sepsis was induced by cecal ligation and puncture. In Group II, experimental sepsis was induced by ascending colon ligation and cecal puncture. Up-and-down method was used to determinate the LC50.

RESULTS

LC50 in Group I was 19 Gauge (Confidence Interval 17 to 22 Gauge). Determination of LC50 was not possible in Group II due to the death of all animals.

CONCLUSION

LC50 in cecal ligation and puncture is 19 Gauge. The lethality of the new model tested in this trial is very high.

Increased NTPDase activity in lymphocytes during experimental sepsis

We investigated in rats induced to sepsis the activity of ectonucleoside triphosphate diphosphohydrolase (NTPDase; CD39; E.C. 3.6.1.5), an enzyme involved in the modulation of immune responses. After 12 hours of surgery, lymphocytes were isolated from blood and NTPDase activity was determined. It was also performed the histology of kidney, liver, and lung. The results demonstrated an increase in the hydrolysis of adenosine-5′-triphosphate (ATP) (P < 0.01), but no changes regarding adenosine-5′-monophosphate (ADP) hydrolysis (P > 0.05). Histological analysis showed several morphological changes in the septic group, such as vascular congestion, necrosis, and infiltration of mononuclear cells. It is known that the intracellular milieu contains much more ATP nucleotides than the extracellular. In this context, the increased ATPasic activity was probably induced as a dynamic response to clean up the elevated ATP levels resulting from cellular death.

Effects of simvastatin in abdominal sepsis in rats

PURPOSE: Statins are widely recognized as hypolipemic drugs, but some studies have observed anti-inflammatory and immunomodulatory effects, known as pleiotropic. The aims of this work was to study possible anti-inflammatory effects of simvastatin in abdominal sepsis. Serum pro-inflammatory cytokines and leukocytes count were determined in an experimental model of abdominal sepsis, using cecal ligation and puncture (CLP) in rats. METHODS: Twenty eigth Wistar rats weighing 285±12g were randomly divided in: CLP/Sinvastatin rats (n=7), treated with 10 mg/Kg of oral simvastatin 18 and 2 hs berofe CLP; CLP/Saline group rats (n=7), treated with oral saline; group Sham/Simvastatin (n=7), treated with simvastatin, and group Sham/Saline (n=7), treated with saline. Serum TNF-alpha, IL-1beta and IL-6 by ELISA and total leukocytes, neutrophils, lymphocytes, and eosinophils were determined 24 hs after CLP. ANOVA and Tukey test were used considering significant p<0.05. RESULTS: It was demonstrated that serum TNF-alpha, IL-1beta and IL-6 were respectively 364,8±42pg/mL; 46,3±18pg/mL and 28,4±13pg/mL in CLP/Sinvastatin rats, significantly lower (p<0.05) than in group CLP/Saline (778,5±86pg/ml; 176,9±46pg/ml; 133,6±21 pg/ml, respectively). The same results were observed in total leukocytes and neutrophils counts. CONCLUSION: These results clearly demonstrate that simvastatin is an effective agent that reduces cytokines levels and leukocyte count in sepsis, independently of its well-known lipid-lowering effects. Thus, HMG-CoA reductase inhibitors like simvastatin have important anti-inflammatory effects in abdominal sepsis in rats.