Resumen de Ultrastructural alterations of the cortical epithelial cells of the rat thymus after cyclophosphamide treatment
S. Yoon, Y. H. Yoo, B.S. Kim, J.B. Kim
A si ngle dose of cyclophosphamide (CY) was administered to Sprague-Dawley rats to investigate the effects of CY on th ymic co rtical epithelial cells (TCE) at the ultrastruc tural leve l. The most striking fi nding amon g th e altera ti o ns in the TCE after CY treatment was a cytoplasmic vacuolization with an increased amount of granular and membranous content.
The granul ar content appeared not only as dense bodies but also as loosely aggregated forms or finely dispersed granules. The membranou s structures appea red in various forms including vesicular, tubular, vacuolar and irregul ar membranous structures and myel in figures.
Some of the membranous structures contained granular materi al. Several vacuoles were closely associated with the endoplasmi c re ticulum (ER). The mo rpho logica l alterations of the ER were also remarkable. The Golgi appa rat us, mitoc hondri a and vesicl es in c reased in number. The cytoplasm became densely granulated due to an increased number of ribosomes and an increased amount of granular material. The tonofil aments 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 sta te of the TCE, probab ly du e to their import ant functions in repopulation and maturation of the cortical thymocy tes during recovery afte r CY-induced acute thymic involution, including the secretio n of some humoral factors.
