The mechanisms responsible for the rapid increases in levels of gonado
tropin and steroid hormones upon administration of cisplatin to rats a
re not clearly understood. In the present study, the morphologic effec
ts of cisplatin on the testis and the relationship of these changes to
serum hormone levels were studied in adult rats. Upon administration
of a single dose (5 mg/kg) of cisplatin, the levels of testosterone in
the peripheral blood decreased and the level of luteinizing hormone (
LH) increased. After 3 days, significant damage to the germinal epithe
lium became detectable by morphologic examination. In Leydig and Serto
li cells, dilatation of the endoplasmic reticulum, structural changes
in mitochondria and an increase in the numbers of inclusion bodies wer
e detected. Although blood-testis barriers between Sertoli cells were
normal, the relationship between germinal cells and the relationship b
etween germinal cells and Sertoli cells were distorted. It is conclude
d that damage to Leydig cells and withdrawal of the controlling effect
s of the germinal epithelium on the LH-Leydig cell axis could explain
the changes in serum hormone levels.