Influence of antibiotics administrated “per os” on intestinal mucosa

Abstract

Introduction: According to academician A.M.Ugolev, the bacterial flora is a necessary attribute of the existence of complex organisms. It is known that the most numerous and complicated by its composition population of bacteria is in the gastro-intestinal tract, particularly in its lower regions. There were made significant advances in the study of the intestinal microbiota and its functional role in humans and animals in recent decades. There is also shown that changing normal intestinal microbiota composition, (the so-called intestinal dysbiosis) as during the administration of antibiotics, leads to a number of disfunctions with severe consequences for the organism.). Literature contains very comprehensive information about the changes in composition of the bacterial flora under the influence of various antibiotics. Although it has very little information about the impact these drugs have on the final stage of the digestive process, which largely determines the overall body metabolism and homeostasis. The purpose of this work was to investigate during the experiments on rats, the effects that Ampicilline and Metronidazole (antibiotics which are widely used in clinic) have on some indicators of the general organism condition, structure of a small and thick intestine, and activity of two intestinal enzymes: transmembrane Maminopeptidase and predominantly of intracellular glycyl-Lleycindipeptidaze, which are carrying out final stages of hydrolysis of proteins. Also there was collected data about the microbiological resistance to these drugs. Materials and methods: Experiments were performed on 30 Wistar rats. During the research was used the combination of two antimicrobial agents: ampicillin and metronidazole, 2% glutaraldehyde solution in a phosphate buffer (PBS), 1% - ethanol solution of 0 s 0 4 , mixture of epone and araldite, toluidine blue. In addition the microtome LKB-III, M BI-6 microscope. Statistical analysis was performed using Student t-test. Results: We have investigated some structural parameters of the small and large intestine, and activity of two intestinal peptide hydrolyses in rats after ampicillin and metronidazole administration during 3 and 5 days. After 3 days of antibiotic administration, the decrease in the weight of mucosa in the small intestine was accompanied with a reduction in the villous height and width in this part of the intestine, and in the weight of mucosa in the colon. At the same time the number of goblet cells in the small intestinal epithelium was increased. Specific activities of aminopeptidase M and glycyl-L-leucine dipeptidase (mmol/min per g) in the mucosa of the small intestine were increased. The total activities (mmol/min calculated per a part of the intestine) of the same enzymes did not change. The administration of antibiotics during 5 days resulted in an increase of specific activity of aminopeptidase M in the mucosa of the proximal part of the small intestine. In the chyme of the small intestine and colon, activities of the same enzymes (mmol/min calculated per a part of the intestine) were increased on the third and fifth days of the antibiotic administration. Conclusions: Thus, the application of ampicillin and metronidazole within 3— 5 days causes a disturbance of the structural and functional parameters in the small and large intestines which is best seen on the third day of the drug administration.