Date of Award
6-1991
Degree Name
Master of Science
Department
Biological Sciences
First Advisor
Dr. Leonard J. Beuving
Second Advisor
Dr. Dale Johnson
Third Advisor
Dr. William Jackson
Access Setting
Masters Thesis-Open Access
Abstract
This study describes morphological changes in the lung at several time intervals following a single injection of 1-Nitronaphthalene (100 mg/kg intraperitoneal) in male Sprague-Dawley rats using transmission and scanning electron microscopy. Dilation of the smooth endoplasmic reticulum and mitochondrial distension in the nonciliated bronchiolar (Clara) cells was apparent as early as 1 hour after injection, while adjacent ciliated cell showed minimal changes. At 6 hours, when respiratory distress was apparent in the animals, Clara and ciliated cells exhibited chromatin clumping, loss of mitochondrial cristae and cytoplasmic vacuolization. Also at 6 hours, the interstitial area around the terminal bronchioles was infiltrated with mast cells and neutrophils. By 24 hours, terminal bronchioles were denuded of epithelial cells and both Clara and ciliated cells in larger bronchioles exhibited mitochondrial distension and cytoplasmic vacuolization. These findings support the theory that initial toxicity occurs in Clara cells through the in situ formation of reactive intermediates and extrabronchiolar injury results from inflammatory responses.
Recommended Citation
Sauer, John-Michael, "1-Nitronaphthalene Causes Ultrastructural Changes Primarily in Nonciliated Bronchiolar Epithelium Followed by Ciliated Epithelium in the Rat" (1991). Masters Theses. 1020.
https://scholarworks.wmich.edu/masters_theses/1020