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Ultrastructural alterations of the cortical epithelial cells of the rat thymus after cyclophosphamide treatment
S. Yoon1, Y.H. Yoo1, B.S. Kim2 and J.J. Kim2
1Department of Anatomy, College of Medicine, Dong-A University, Pusan, South Korea and
2Department of Anatomy, College of Medicine, Pusan University, Pusan, South Korea
Offprint requests to: Dr. Sik Yoon, Department of Anatomy, College of Medicine, Dong-A University, 3-1 , Dongdaesin-dong, Seo-gu, Pusan,
602-103, South Korea
Summary. A single dose of cyclophosphamide (CY)
was administered to Sprague-Dawley rats to investigate
the effects of CY on thymic cortical epithelial cells
(TCE) at the ultrastructural level. The most striking
finding among the alterations in the TCE after CY
treatment was a cytoplasmic vacuolization with an
increased amount of granular and membranous content.
The granular content appeared not only as dense bodies
but also as loosely aggregated forms or finely dispersed
granules. The membranous structures appeared in
various forms including vesicular, tubular, vacuolar and
irregular membranous structures and myelin figures.
Some of the membranous structures contained granular
material. Several vacuoles were closely associated with
the endoplasmic reticulum (ER). The morphological
alterations of the ER were also remarkable. The Golgi
apparatus, mitochondria and vesicles increased in
number. The cytoplasm became densely granulated due
to an increased number of ribosomes and an increased
amount of granular material. The tonofilaments lost their
original array and increased in amount. The cell surface
exhibited many cytoplasmic processes like microvilli. It
seems that the above features result not only from some
damage by CY, but are also signs of a hyperfunctional
state of the TCE, probably due to their important
functions in repopulation and maturation of the cortical
thymocy tes during recovery after CY-induced acute
thymic involution, including the secret ion of some
humoral factors. Histol Histopathol 12, 401-413 (1997)
Key words: Thymic cortical epithelial cell,
Cyclophosphamide, Ultrastructure, Vacuole, Rat
DOI: 10.14670/HH-12.401
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