ObjectiveTo investigate the changes of autophage-related protein in lung tissues of rats with chronic obstructive pulmonary disease (COPD). MethodsPassive cigarette smoking was used to establish COPD model in rats. The mRNA and protein expressions of PI3K, total AKT, phosphorylated-AKT, total mTOR, phosphorylated-mTOR, and autophagy-related genes including LC3Ⅱ/Ⅰ, Beclin1, Atg5, Atg7, Atg12, P62 in lung tissues were measured by real-time PCR and Western blot. The autophagy level was compared between the COPD rats and the normal rats by LC3B immunohistochemistry. ResultsReal-time PCR analysis showed that the mRNA expressions of Beclin1, Atg5 and Atg12 significantly increased in lung tissues of the COPD rats compared with the normal rats (all P < 05). There was no significant difference between the COPD rats and the normal rats as for Atg7 mRNA expression (P > 0.05). Western blot analysis showed that the protein expressions of PI3K, p-AKT/AKT and p-mTOR/mTOR significantly decreased, the protein expressions of LC3 Ⅱ/Ⅰ, Atg5, and Beclin1 increased, and protein expression of P62 significantly decreased in lung tissues of the COPD rats compared with the normal rats (all P < 05). LC3B immunohistochemistry showed that the LC3B expression was higher in the COPD rats than that in the normal rats. ConclusionThe level of autophagy significantly increases in COPD rats with decreased expression of upstream proteins in autophagy signal pathway and increased expression of autophage proteins.
This paper investigates the variation of lung tissue dielectric properties with tidal volume under in vivo conditions to provide reliable and valid a priori information for techniques such as microwave imaging. In this study, the dielectric properties of the lung tissue of 30 rabbits were measured in vivo using the open-end coaxial probe method in the frequency band of 100 MHz to 1 GHz, and 6 different sets of tidal volumes (30, 40, 50, 60, 70, 80 mL) were set up to study the trends of the dielectric properties, and the data at 2 specific frequency points (433 and 915 MHz) were analyzed statistically. It was found that the dielectric coefficient and conductivity of lung tissue tended to decrease with increasing tidal volume in the frequency range of 100 MHz to 1 GHz, and the differences in the dielectric properties of lung tissue for the 6 groups of tidal volumes at 2 specific frequency points were statistically significant. This paper showed that the dielectric properties of lung tissue tend to vary non-linearly with increasing tidal volume. Based on this, more accurate biological tissue parameters can be provided for bioelectromagnetic imaging techniques such as microwave imaging, which could provide a scientific basis and experimental data support for the improvement of diagnostic methods and equipment for lung diseases.