In vivo effects of endotoxin on DNA synthesis in rat nasal epithelium

Journal Article · Wed Dec 01 04:00:00 EST 1993 · Microscopy Research and Technique; (United States)

DOI:https://doi.org/10.1002/jemt.1070260513· OSTI ID:5346007

Harkema, J R; Hotchkiss, J A ^[1]

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1. Inhalation Toxicology Research Inst., Albuquerque, NM (United States)

Airway inflammation in bacterial infections is characterized by the presence of neutrophils and often epithelial injury and repair. Release of endotoxin from bacteria may contribute to these processes. The purpose of this study was to determine the in vivo effects of repeated endotoxin exposure on DNA synthesis in rat nasal epithelium in the presence and absence of neutrophilic influx. Rats were intranasally instilled, once a day for 3 days, with endotoxin or saline (controls). Before the first and third instillations, half of the saline and endotoxin-instilled animals were depleted of circulating blood neutrophils by administering a rabbit anti-rat neutrophil antiserum. Rats were sacrificed 6 or 24 h after the last instillation. Two hours prior to sacrifice, rats were intraperitoneally injected with bromodeoxyuridine (BrdU), an analog of thymidine that is incorporated in the nucleus of cells in the S-phase of the cell cycle. Nasal tissues were processed for light microscopy and immunohistochemical detection of BrdU in nasal epithelial cells. The numbers of nasal epithelial cells, BrdU-labeled epithelial nuclei, and neutrophils per millimeter of basal lamina in the epithelium lining the nasal turbinates in the proximal nasal passages were determined by morphometric analysis. The authors did not observe a neutrophilic influx in the nasal tissues of neutrophil-depleted rats at 6 or 24 h after the last endotoxin instillation; however, the numbers of nasal epithelial cells and the BrdU-labeling index were significantly increased compared to saline-instilled controls. In contrast, non-neutrophil-depleted rats instilled with endotoxin had a marked neutrophilic influx, but no significant differences in the number of nasal epithelial cells at 6 or 24 h, compared to controls. In addition, the BrdU-labeling index in neutrophil-sufficient rats was increased only 6 h after the last instillation, compared to controls.

• OSTI ID: 5346007
• Journal Information: Microscopy Research and Technique; (United States), Journal Name: Microscopy Research and Technique; (United States) Vol. 26:5; ISSN 1059-910X; ISSN MRTEEO
• Country of Publication: United States
• Language: English

Related Subjects

550900* -- Pathology
59 BASIC BIOLOGICAL SCIENCES
ANIMAL TISSUES
ANTIGENS
BACTERIAL DISEASES
BIOLOGICAL EFFECTS
BODY
DISEASES
DNA REPLICATION
ENDOTOXINS
EPITHELIUM
HAZARDOUS MATERIALS
INFECTIOUS DISEASES
MATERIALS
NUCLEIC ACID REPLICATION
PATHOGENESIS
TISSUES
TOXIC MATERIALS
TOXINS