Toxicology 163 (2001) 163 – 174
Evaluation of teniposide (VM-26)-induced toxicity on mouse
spermatogenesis by flow cytometry
P. Jyothi, Ganesh Chandra Jagetia *, H. Krishnamurthy
Department of Radiobiology, Kasturba Medical College, Manipal -576 119, India
Received 22 July 2000; received in revised form 25 January 2001; accepted 10 April 2001
Abstract
Alteration in the testicular weight and various germ cell populations was studied in male mice treated with different
doses (0.05, 0.25, 0.5, 1.0 and 2.0 mg/kg b. wt.) of teniposide (VM-26) at various post-treatment time periods.
Treatment of mice with different doses of teniposide did not significantly alter the testicular weights, irrespective of
the drug dose used. Flow-cytometric analysis of germ cells of the untreated control mice testes revealed four distinct
DNA peaks corresponding to elongated spermatids (HC), round spermatids (1C), spermatogonia and non-germ cells
(2C) and primary spermatocytes (4C). The region between 2C and 4C peaks represents cells that are actively
synthesizing DNA (S-phase cells). Treatment of mice with different doses of teniposide resulted in a significant
depletion in the relative percentage of spermatogonia from day 2 to 35 post-treatment depending on the drug dose.
DNA-synthesizing, i.e. S-phase, cells declined significantly at day 1 post-treatment and continued to decline up to day
70 post-treatment for all the drug doses studied, except 2 mg/kg drug dose at day 28 post-treatment. A significant
decline in the relative percentage of primary spermatocytes (4C) was observed at day 7 that continued up to day 70
post-treatment depending on the drug dose. Round spermatids (1C) declined significantly at day 21 post-treatment
after administration of 0.25 – 2.0 mg/kg VM-26. The relative percentage of elongated spermatids showed a significant
decline at day 28 after 1 and 2 mg/kg drug treatment. These alterations in different germ-cell populations are reflected
in the various germ-cell ratios. The 4C:2C ratio showed a significant decline at day 7 and 14 post-treatment after 1
and 2 mg/kg VM-26 treatment, while the 1C:2C ratio declined significantly at day 21 post-treatment in the mice
treated with 0.5 and 2.0 mg/kg of VM-26. 4C:S-phase and 1C:4C ratios increased significantly from day 1 to 70
post-treatment, depending on the drug dose. Our study demonstrates that the treatment of mice with low doses of
VM-26 exerts cytotoxic effects on various germ-cell populations. © 2001 Elsevier Science Ireland Ltd. All rights
reserved.
Keywords: Flow cytometry; Mouse; Primary spermatocytes; S-phase cells; Spermatogenesis; Teniposide; Testes
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1. Introduction
Teniposide (VM-26), 4-demethylepipodoph-
yllotoxin-4-(4,6-o -thenylidine-(D-glucopyranoside)
is a semi-synthetic podophyllotoxin, which is an
* Corresponding author. Tel.: +91-8252-71201, ext: 2122;
fax: +91-8252-70062.
E-mail address: gcjag@usa.net (G.C. Jagetia).
0300-483X/01/$ - see front matter © 2001 Elsevier Science Ireland Ltd. All rights reserved.
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