RESUMEN
The lecture is devoted to the morphological characteristics of the maturation of lung tissue structures in the fetal period. Fetal histology of the lungs presents the intrauterine development of lung tissue in four successive stages: pseudoglandular, canalicular, saccular and alveolar, each has specific morphological criteria. The following morphological features are predetermined: the development of alveolar epithelium, the ratio of mesenchyme towards the area in alveolar spaces, the degree of proliferation and location of vessels of the microcirculatory bed towards prealveolar partitions. During the fetal period the alveolar columnar epithelium is flattened and differentiates into alveolocytes type I and II, the area of the mesenchyme gradually decreases and by the birth of a full-term newborn kid it is present mainly in the thickness between the alveolar septa, microcirculation vessels, initially laying deep in the thickness of the mesenchymal tissue, gradually proliferate, approach the pre-alveolar epithelium, channeling it with the formation of alveolar capillary membranes. Air exchange in the lung tissue is mainly provided with two factors: the presence of second-order alveolocytes capable of producing surfactant, and a sufficient formation of alveoli as well. This work summarizes the basics of fetal lung histology with the demonstration of histological preparations of the lungs at different stages of intrauterine development.
Asunto(s)
Feto , Pulmón , Recién Nacido , Humanos , Edad Gestacional , Microcirculación , EpitelioRESUMEN
BACKGROUND: In recent years, attention of the scientific community has been drawn to the study of the role of homocysteine in the pathology of diseases in general and the respiratory system in particular. Violations of the synthesis and disposal of homocysteine are the cause of its excessive accumulation in the body, which subsequently leads to damage to all organs and systems. METHODS: We conducted this study on 64 white non-linear rats of 6-8 and 24-26 months old rats, which were divided into two control and experimental groups during the experiment. The study of ultrastructural changes in the lungs of rats was performed using an electron microscope. RESULTS: The results of the conducted study show that all the animals of the experimental group, corresponding to 32 (50%) cases, possess conspicuous morphological changes in the structure of the lungs. The specific features of mature animals were the narrowing of the alveolar space of the part of the alveoli and the increase in the number of macrophages in them. Partial desquamation of capillary endothelial lining and a slight increase of collagen fibers in interalveolar membranes were observed compared to control animals. A characteristic feature for older animals was the growth of connective tissue, predominantly collagen fibers, which led to pneumosclerosis. The thickening of the aerogemic barrier was also detected, and the endothelial lining was intermittent or desquamated. CONCLUSION: Mature animals of the experimental group were characterized by activation of inflammatory processes, oxidative stress, due to increased production of macrophages and, as a consequence, the launch of the humorous link of immunity, while in old rats were determined by fibrosis, disorders of the trophic and gas metabolism, as well as damage to the endothelium part of lungs.
Asunto(s)
Hiperhomocisteinemia/complicaciones , Hiperhomocisteinemia/patología , Pulmón/patología , Animales , Modelos Animales de Enfermedad , Endotelio Vascular/patología , Macrófagos Alveolares/patología , Masculino , RatasRESUMEN
We studied the effect of diindolylmethane in a dose of 600 mg/kg on the change in adhesion strength of alveolocytes and hepatocytes in CBA mice. Diindolylmethane was administered intragastrically to experimental animals for 10 days, controls intragastrically received an equivalent volume of saline. At the end of the therapeutic period, mice treated with diindolylmethane showed a significant increase in the adhesion strength of alveolocytes by 16% (p=0.003) and hepatocytes by 61% (p=0.0001) in comparison with the control group, which indicates the antipromotor activity of diindolylmethane.
Asunto(s)
Hepatocitos/efectos de los fármacos , Indoles/farmacología , Alveolos Pulmonares/efectos de los fármacos , Animales , Ratones , Alveolos Pulmonares/citologíaRESUMEN
In CBA mice infected with influenza viruses A/H1N1/California/04/2009 and A/H5N1/Goose/Krasnoozerskoye/627/05 in a dose of 10 MLD50, the mechanisms of death of pulmonary alveolocytes over 10 postinfection days were studied by light microscopy, immunohistochemistry, and morphometry. In mice infected with A/H1N1, alveolocytes died predominantly via necrosis, while apoptosis mostly employed the mitochondrial pathway. In mice infected with A/H5N1, apoptosis was the dominant mechanism of alveolocyte death proceeded via membrane receptor signaling followed by switching to FAS-mediated pathway via activation of FADD, the apoptotic signal transduction protein.