Histophysiology of the lungs and oxygen transport function of the blood with an exclusively fatty diet

Abstract

Objective: To study of the histophysiology of the lungs and the oxygen transport function of blood in rats fed by an extreme fatty diet for 30 days. Methods: The study design is a randomized experimental study. The work was carried out on white, mongrel male rats weighing 200-250g. During the 30 days period of time, 10 animals were fed exclusively with animal fat. Then the animals were slaughtered under general anesthesia, after preliminary blood sampling for subsequent determination of the lactate level and oxygen transport function of the blood. Histological preparations of the lungs were stained with hematoxylin-eosin and Van Gieson. Histological analysis of lung components was performed using the application for measuring microscopic objects Tor View. For statistical analysis, the Student's criterion was applied for independent and paired samples in the SPSS 22.0 program. Results: An extreme fat diet consisting of 100% animal fat led to an increase in serum lactate level (0.79 (0.78)) vs 1.92 (0.28)) (p<0.001). Oxygen transport function decreased in animals of the dietary intervention group. The ratio of the rate of oxygen transport by arterial blood (VaVO2) to the rate of its consumption by tissues (VO2) in the main group decreased by 3 times (4.44 (0.47)) due to a pronounced decrease in the rate of oxygen transport by arterial blood (4.1042 (0.091)) vs. 64.4060 (0.14)) (p<0.001). There was a 2-fold shift of the buffer bases towards its decrease in the animals of the main group as compared to control (4.9764 (0.81) versus 8.19 (0.22)) (p<0.001). Remodeling of the histophysiology of the bronchial tree and branches of the pulmonary artery was characterized by pronounced heterogeneity, depending on the level of division (large, medium, bronchioles) of the bronchi and the associated pulmonary and bronchial arteries. At the level of the alveolar tree, areas of atelectasis with blood deposition and emphysema of the acinar apparatus of the lungs were observed. And at the level of the microcirculatory bed intravascular, vascular, and circulatory changes were noted. Conclusions: A 30-day feeding of male rats exclusively with sheep fat led to an increase in lactic acid concentration, a decrease in the rate of oxygen transport by arterial blood and a deficiency of blood buffer bases, which were combined with microcirculatory changes, and at the alveolar level with foci of atelectasis with blood deposition, emphysema and inflammatory reaction.

Keywords

• high-fat diet
• rats
• airway remodeling
• acid-base equilibrium
• pulmonary gas exchange
• lactic acid