Hümeyra Ünsal

The expression of matrix metalloproteinases 8 and 9 by neutrophils of wistar albino rats with severe qualitative and quantitative protein malnutrition

Neutrophils are the major cellular immune components in response to bacterial infections. Neutrophil enzymes are important in invasion, inflammation, and infection processes. In order to understand the basic effects of protein malnutrition on neutrophils we studied matrix metalloproteinases 8 and 9 (MMP-8 and MMP-9) production in severe quantitative and qualitative protein malnutrition in rats. Wistar rats (2 months old) were divided into four groups each with three subgroups and fed various protein-containing diets (24% protein, 20% gelatin-containing and N-free) for 7, 14, 21, and/or 28 days. Neutrophil enzyme expression was determined by Western blotting. Leukocytes decreased significantly due to malnutrition (p = 0.001 ) whilst the percentage of neutrophils increased (p = 0.02) in protein-deprived groups. Neutrophils of malnourished rats produced lower levels of MMP-8 at early stages of protein deprivation with an increase in the following weeks. MMP-9 production by neutrophils from N-free diet fed animals was highest after one week. Serum MMP-9 levels decreased in the qualitative but not in the quantitative protein malnutrition groups. Results suggest that neutrophils might be important in reuse of body cell proteins during fasting or malnutrition conditions and dietary manipulation might have profound effects on MMP-8 and -9 production in rats.

Time-dependent effects of dietary qualitative and quantitative protein malnutrition on some members of the cecal microbiota in male Wistar rats

Objective: Protein deficiencies are common conditions around the world. They may affect organisms directly or indirectly by changing their normal microbiota. This study aimed to determine time-dependent effects of the quality and quantity of dietary proteins on intestinal microbiota. Materials and methods: Sixty young male Wistar rats were used in four experiments with durations of 1, 2, 3 or 4 weeks, respectively. In each experiment 15 animals were divided into 3 equal groups and given either a complete rat chow (controls) or semi-synthetic diets containing almost no protein (N-free) or 20% gelatin ad libitum. Total aerobes, Enterobacteriaceae, coliform, and lactobacilli colonies were counted in cecal contents. Results: Generally, total aerobic bacteria and lactobacilli were most affected by protein malnutrition in all experiments. Both types of protein malnutrition decreased the numbers of total aerobic bacteria in all experiments except for the gelatin-fed animals in experiment I. Mean lactobacilli counts also decreased in both malnutrition groups but the decrease in lactobacilli count was more severe in N-free groups than in gelatin-fed groups. Conclusion: These results suggest that the effects of dietary proteins on cecal bacteria are dependent on the type of bacteria and partly time-dependent.