PRELIMINARY-RESULTS OF ETHYLNITROSOUREA, ISOPROPYL METHANESULFONATE AND METHYL METHANESULFONATE ACTIVITY IN THE TESTIS AND EPIDIDYMAL SPERMATOZOA OF MUTA(TM) MICE
Jd. Mattison et al., PRELIMINARY-RESULTS OF ETHYLNITROSOUREA, ISOPROPYL METHANESULFONATE AND METHYL METHANESULFONATE ACTIVITY IN THE TESTIS AND EPIDIDYMAL SPERMATOZOA OF MUTA(TM) MICE, Mutation research. Genetic toxicology and environmental mutagenesis, 388(2-3), 1997, pp. 123-127
Male Muta(TM) Mice were given a single intraperitoneal dose of either
1/15 M phosphate buffer (pH 6) as the vehicle control, MMS 40 mg/kg, E
NU 150 mg/kg or iPMS 200 mg/kg, at a dose volume of 20 ml/kg. Animals
from each group were killed 3 or 63 days after dosing, the DNA extract
ed from whole testes and epididymal spermatozoa and analysed for mutat
ion frequency. In the testes, no increase in mutation frequency was ob
served, at either timepoint, for the animals treated with either MMS o
r iPMS. A slight increase in the mutation frequency, above vehicle con
trol values, was seen in the ENU-treated animals with a 3 day expressi
on time. A 4-fold increase was observed in the ENU-treated animals exp
osed for 63 days. In the epididymal spermatozoa, all of the test chemi
cals induced increases in mutation frequency, at both timepoints, with
the exception of a negative result for MMS after 3 days. ENU induced
a 2.5 and iPMS a induced a 4-fold increase above the control mutation
frequency after 3 days. For all treatments, the later sampling time of
63 days gave an approximate 2-fold increase above the results of the
3-day timepoint. These increases amounted to a 2, 4.5 and Ii-fold incr
ease above control for MMS, ENU and iPMS, respectively. The Muta(TM) M
ouse positive selection system appears to be sensitive to both the pre
meiotic germ cell mutagen, ENU and postmeiotic germ cell mutagens, MMS
and iPMS.