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Mutation Research, 260 (1991) 311 © 1991 Elsevier Science Publishers B.V. 0165-1218/91/$03.50 ADONIS 016512189100111G
MUTGEN 01708
Series: 'Current Issues in Mutagenesis and Carcinogenesis', No. 28
Methyl carbamate: Negative results in mouse bone-marrow micronucleus test M.D. Shelby a and R.R. Tice b National Toxicology Program, National Institute of Encironmental Health Sciences, P.O. Box 12233, Research Triangle Park, NC 27709 (U.S.A.) and b Integrated Laboratory Systems, lnc., P.O. Box 13501, Research Triangle Park, NC 27709 (U.S.A.) (Accepted 23 April 1991)
Keywords: Micronucleus; Short-term test; Cytogenetics, in vivo
Methyl carbamate (CAS No. 598-55-0) was tested for its ability to induce micronucleated polychromatic erythrocytes (MN-PCE) in the bone marrow of male B6C3F1 mice. The compound was dissolved in phosphate-buffered saline and administered by intraperitoneal injection at a volume of 0.4 ml. Using 5 animals per treatment group, the compound was administered on each of 3 consecutive days and bone-marrow samples were taken 24 h following the third treatment. Using acridine orange staining, 2000 PCE were scored from each animal to determine the frequency of MN-PCE and the %PCE was determined in 200 cells. For details of the protocol see Tice et al. (1990). Ethyl carbamate (urethane) has been shown to induce MN-PCE in mouse bone marrow following a similar, 3-exposure protocol (Holmstrom, 1990). Table la shows that the frequency of MN-PCE was not increased by treatment with doses up to 2000 m g / k g / d a y . Likewise, there was no effect on the %PCE. Table lb shows the results of a second test in which the high dose was raised to 3000 m g / k g / d a y . Again there was no effect on the frequency of MN-PCE or on the %PCE.
Correspondence: Dr. M.D. Shelby, National Toxicology Program, National Institute of Health Sciences, P.O. Box 12233, Research Triangle Park, NC 27709 (U.S.A.)
TABLE 1 RESULTS OF MOUSE BONE MARROW MICRONUCLEUS TESTS ON METHYL CARBAMATE
(a)
(b)
Dose MN-PCEper S.E.M. (mg/kg/day) 1000 PCE
%PCE S.E.M,
0 500 1000 2000
3.70 2.80 1.70 1.80
0.58 0.92 0.34 0.46
59.6 61.9 53.7 56.7
2,50 2.13 1.90 1.75
MMC (0.2)
8.60
1.52
55.8
2.50
0 2000 2500 3000
2.30 1.90 1.70 1.67
0.72 0.29 0.51 1.01
63.0 63.9 63.9 60.2
3.67 1.82 1.89 4.48
MMC (0.2)
4.70
0.56
58.5
1.79
MN-PCE and %PCE data are presented as group means and standard errors of the means among animals. One-tailed trend tests (see Tice et al., 1990) indicated that methyl carbamate did not significantly increase the frequency of MN-PCE or reduce the %PCE. MMC, mitomycin C.
References Holmstrom, M. (1990) Induction of micronuclei in bone marrow of mice exposed to 1, 2 or 3 daily doses of urethane, Mutation Res., 234, 147-154. Tice, R.R., G.L. Erexson, C,J. Hilliard, J.L. Huston, R.M. Boehm, D. Gulati and M.D. Shelby (1990) Effect of treatment protocol and sample time on the frequencies of micronucleated polychromatic erythrocytes in mouse bone marrow and peripheral blood, Mutagenesis, 5, 313-321.
Mutation Research, 260 (1991) 311 © 1991 Elsevier Science Publishers B.V. 0165-1218/91/$03.50 ADONIS 016512189100111G
MUTGEN 01708
Series: 'Current Issues in Mutagenesis and Carcinogenesis', No. 28
Methyl carbamate: Negative results in mouse bone-marrow micronucleus test M.D. Shelby a and R.R. Tice b National Toxicology Program, National Institute of Encironmental Health Sciences, P.O. Box 12233, Research Triangle Park, NC 27709 (U.S.A.) and b Integrated Laboratory Systems, lnc., P.O. Box 13501, Research Triangle Park, NC 27709 (U.S.A.) (Accepted 23 April 1991)
Keywords: Micronucleus; Short-term test; Cytogenetics, in vivo
Methyl carbamate (CAS No. 598-55-0) was tested for its ability to induce micronucleated polychromatic erythrocytes (MN-PCE) in the bone marrow of male B6C3F1 mice. The compound was dissolved in phosphate-buffered saline and administered by intraperitoneal injection at a volume of 0.4 ml. Using 5 animals per treatment group, the compound was administered on each of 3 consecutive days and bone-marrow samples were taken 24 h following the third treatment. Using acridine orange staining, 2000 PCE were scored from each animal to determine the frequency of MN-PCE and the %PCE was determined in 200 cells. For details of the protocol see Tice et al. (1990). Ethyl carbamate (urethane) has been shown to induce MN-PCE in mouse bone marrow following a similar, 3-exposure protocol (Holmstrom, 1990). Table la shows that the frequency of MN-PCE was not increased by treatment with doses up to 2000 m g / k g / d a y . Likewise, there was no effect on the %PCE. Table lb shows the results of a second test in which the high dose was raised to 3000 m g / k g / d a y . Again there was no effect on the frequency of MN-PCE or on the %PCE.
Correspondence: Dr. M.D. Shelby, National Toxicology Program, National Institute of Health Sciences, P.O. Box 12233, Research Triangle Park, NC 27709 (U.S.A.)
TABLE 1 RESULTS OF MOUSE BONE MARROW MICRONUCLEUS TESTS ON METHYL CARBAMATE
(a)
(b)
Dose MN-PCEper S.E.M. (mg/kg/day) 1000 PCE
%PCE S.E.M,
0 500 1000 2000
3.70 2.80 1.70 1.80
0.58 0.92 0.34 0.46
59.6 61.9 53.7 56.7
2,50 2.13 1.90 1.75
MMC (0.2)
8.60
1.52
55.8
2.50
0 2000 2500 3000
2.30 1.90 1.70 1.67
0.72 0.29 0.51 1.01
63.0 63.9 63.9 60.2
3.67 1.82 1.89 4.48
MMC (0.2)
4.70
0.56
58.5
1.79
MN-PCE and %PCE data are presented as group means and standard errors of the means among animals. One-tailed trend tests (see Tice et al., 1990) indicated that methyl carbamate did not significantly increase the frequency of MN-PCE or reduce the %PCE. MMC, mitomycin C.
References Holmstrom, M. (1990) Induction of micronuclei in bone marrow of mice exposed to 1, 2 or 3 daily doses of urethane, Mutation Res., 234, 147-154. Tice, R.R., G.L. Erexson, C,J. Hilliard, J.L. Huston, R.M. Boehm, D. Gulati and M.D. Shelby (1990) Effect of treatment protocol and sample time on the frequencies of micronucleated polychromatic erythrocytes in mouse bone marrow and peripheral blood, Mutagenesis, 5, 313-321.
