Since the ability of alveolar epithelial cells to ingest inhaled fine particles has not been characterized in detail, the present study seeks to evaluate this physiological activity. We used a 0.2% suspension of intact or lecithin-coated polystyrene latex beads (240 nm in diameter). A 5-ml suspension of intact or lecithin-coated latex beads was intratracheally administered to rats using a compressor nebulizer. Thereafter, the lungs were perfused intratracheally with glutaraldehyde solution and cut into small pieces. The samples were postfixed with osmium tetroxide, embedded in epoxy resin and examined under an electron microscope. Both lecithin-coated and uncoated beads were incorporated into alveolar macrophages. Some of the ingested beads in the alveolar macrophages were sequestered within lysosomes. Types I and II alveolar epithelial cells selectively incorporated only lecithin-coated beads, which were also observed within the cytoplasm of monocytes in the capillary lumen. These findings suggest that alveolar epithelial cells can incorporate exogenous particles, which are then transferred from the alveoli to intravascular spaces by transcytosis.
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http://dx.doi.org/10.1007/s00441-002-0647-3 | DOI Listing |
Nanomaterials (Basel)
December 2024
Former Japan Bioassay Research Center, Hadano 257-0015, Kanagawa, Japan.
The purpose of the present study is to contribute to the establishment of a standard method for evaluating the adverse effects of nanomaterials by intratracheal administration. Low and high doses of multi-walled carbon nanotubes (MWCNTs) were administered to rats in a single administration or the same final dose as the single administration but divided over four administrations. Bronchoalveolar lavage examination on day 14 showed an inflammatory reaction and cytotoxicity in the lung, generally greater at the higher dose, and tending to be greater in the rats with four administrations at both the low and high doses.
View Article and Find Full Text PDFCancer Sci
December 2024
Division of Molecular Therapeutics, Aichi Cancer Center Research Institute, Nagoya, Japan.
KRAS was long deemed undruggable until the discovery of the switch-II pocket facilitated the development of specific KRAS inhibitors. Despite their introduction into clinical practice, resistance mechanisms can limit their effectiveness. Initially, tumors rely on mutant KRAS, but as they progress, they may shift to alternative pathways, resulting in intrinsic resistance.
View Article and Find Full Text PDFDiscov Med
December 2024
Department of Respiratory Medicine, The First Affiliated Hospital of Anhui University of Chinese Medicine, 230031 Hefei, Anhui, China.
Background: Chronic obstructive pulmonary disease (COPD) is a prevalent yet manageable respiratory condition. However, treatments presently used normally have side effects and cannot cure COPD, making it urgent to explore effective medications. The ginsenoside Rg3 (Rg3) has been shown to have anti-inflammatory and anti-tumor properties and can improve COPD.
View Article and Find Full Text PDFCell Mol Life Sci
December 2024
National Engineering Research Center for Bioengineering Drugs and the Technologies, Institute of Translational Medicine, Jiangxi Medical College, Nanchang University, Nanchang, 330031, China.
Idiopathic pulmonary fibrosis (IPF) is a prevalent interstitial lung disease with high mortality. CD38 is a main enzyme for intracellular nicotinamide adenine dinucleotide (NAD) degradation in mammals. It has been reported that CD38 participated in pulmonary fibrosis through promoting alveolar epithelial cells senescence.
View Article and Find Full Text PDFMatrix Biol
December 2024
Departamento de Bioquímica y Biología Molecular, Universidad de Salamanca, Instituto de Investigación Biomédica de Salamanca (IBSAL). Electronic address:
The lung is a highly vascularized tissue that often harbors metastases from various extrathoracic malignancies. Lung parenchyma consists of a complex network of alveolar epithelial cells and microvessels, structured within an architecture defined by basement membranes. Consequently, understanding the role of the extracellular matrix (ECM) in the growth of lung metastases is essential to uncover the biology of this pathology and developing targeted therapies.
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