Document 6B4zMNQYLKOmRz9kG2z3zX9Yo

T0XSTUDIES1911 Ilf:'., IM-?:' 'i*1 . r. ' ?itV ?v X : * T?% MuMmoI- BIO-TEST Jatxmbyuei. Ate. ieiO fBONTACt RO/D NORTHBROOK. IlltNO'S 60062 January 13, 1972 ' V-, `V4-;;^^.S ;^5i1 ;zsfr Mr. Elmer P. Wheeler Manager, Environmental Health ' Monsanto Company 800 N. Lindbergh Boulevard St. Louis, Missouri 63166 Dear Mr. Wheeler: Re: 1BT No. E623 - Mutagenic Study with Aroclor 1260 in Albino Mice We are submitting herewith our laboratory report dated January 13, 1972, prepared in connection with the above study. Very truly yours, 36 X* t J, C. Calandra President .... JCC/kjl TOXSTUDIES1912 T0XSTUDIES1913 . ,w.<w BIO-TEST . .. ... II, Summary - ' ~ - r I.,.';'---'-..................... ...... '. r A dominant lethal mutagenie study was conducted using albino mice, ' ' Males were treated with a single intraperitoneal injection of Aroclor 1260 at levels of either 500 (T-I) or 1,000 (T-- II) mg/kg of body weight. Another group of males received methyl methanesuLfonate (MMS) at 100 mg /kg and was used as a positive control. Mating indices for Aroclor 1260 treated animals were unaffected. Two positive control males and 1 T-I male died during the course of the study. Data for treated animals regarding implantation sites, resorption sites, and embryos did not differ from the control data. Mutation rates were not unusual for the Aroclor treated animals. MMS treated animals showed a positive response for the first 2 weeks following treatment. Therefore, treating male mice with Aroclor 1260 via an intraperitoneal injection of 500 or 1,000 mg/kg did not causo a dominant lethal response;- Respectfully submitted, INDUSTRIAL BIO-TEST LABORATORIES, INC. Report prepared by: Dennis Arnold, B.S. Croup Leader Mutagenic Studies ^ Report approved by: Gerald Kennedy,^Ts. Senior Croup Leader Metabolic and Mutagenic Studies January 13, 1972' 0365755.09 TOXSTUDIES1914 , * _ ' 'r , ' *y III. Procedure .. ' .v. A. Outline of Experiment . The test material was Aroclor 1260. Methyl methanesulfonate was used as a positive control. Charles River strain albino mice were received at this laboratory at 60 to 70 days of age for use in the study. The organi zation of groups is presented in Table I. Group C PC T-I T-U TABLE I TEST MATERIAL: Aroclor 1260 Mutagenic Study - Albino Mice Organization of Groups Dose Level* (mg /kg) 100 500 1,000 Number of Males Treated 12 12 12 12 * Aroclor 1260 was administered as a 10 percent solution in corn oil. Control males received the vehicle in amounts equivalent to those received by the T-U males. Positive control males received methyl methanesulfonate in a 1 percent corn oil solution. 0365755.05 TOXSTUDIES1915 3*4**lU*al BIO T $ T JoU*o(>*iei, : ~fr> f r- B. Dosage Levels . :: The-treatment levels were selected by Intraperitoneal adminis- ' , (ration of single graded doses of the test material to male mice. The .* maximum tolerated dose was determined and dose levels employed In the main study were based on these findings. The test material was adminis- - tered intraperitoneally in a corn oil solution to male mice. Control animals received the vehicle in volumes equivalent to those giver the high test group and positive control males received methyl methane sulfonate, C, Mating Schedule Each group consisted of 12 male mice, each of which was placed in a cage with 3 untreated virgin females immediately after dose adminis tration. At the end of l week, the females were removed from the cage and replaced by another group of 3 females. This procedure continued for 6 consecutive weeks, a period of time required for maturation of the male mouse germ cells from the spermatocyte to the mature spermatozoon. Experiments at this laboratory have shown that the reference mutagenic compound* affects germinal cells in the meiotic and post-xneiotic stages prior to or during the spermatid stage. Recovery from the effects of MMS - is generally seen 3 weeks post-treatment. Following the sixth week of mating, all males were sacrificed. D, Female Sacrifice The females were sacrificed approximately 1 week after re moval from the breeding cage, at which time most females that had * The reference mutagen Is methyl methanesulfooate (MM5V* _ V ' 0365755.06 TOXSTUDIES1916 Industrial BHOTTEST daiaraiouM, fne.- - ' < :/ '*. -^5- v- mated were at mid-pregnancy. All animal* were sacrificed by carbon dioxide asphyxiation. The numbers of Implantation Bites, resorption sites, and embryos were recorded. Females were judged to be pregnant if corpora lutea were present in the ovaries. Resorption sites were divided into 2 groups, early deaths (deciduomata) and late deaths. Late deaths refer to embryos which develop to a relatively advanced stage prior to death, so that the placenta and fetal membranes or remnants thereof are visible. The frequency of late deaths is apparently unaffected by mutagens and. therefore, would appear to be non-genetic in this test system. Oeciduomata occur at the sites of implanted blastocysts which fail to develop following implantation. The mutagenicity of the chemical can be measured by the proportions of all implantations which are deciduomata. Mutagenicity can also be measured by comparing the mean num ber of viable embryos in the test group to the number obtained in the con trol group. Calculation of the mutation rate using this criterion assume* that pre-implantation losses among non-affected test animals will be es sentially the same as losses observed among control animals. 0365755.07 TOXSTUDIES1917 BIO-TEST AAimAw, jUi . IV. Results , A. Treatment Levels '- . , ^ Doses were administered to groups of 4 male mice each to . determine the levels for the main study. Exposures of 30, 100, 3oo, or - . 1, 000 mg of Aroclor 1260 per kg of body weight failed to elicit any abnormal reactions and no deaths were recorded during the 14-day observation period following treatment. B. Mortality and Reactions Two positive control males (weeks 1 and 3) and 1 T-I male (week 3) died during the study. No other deaths occurred. C. Mating Performance Mating indices, defined as the number of ammals pregnant divided by the number of females mated times 100, and the number of surviving males for each post-treatment week are shown in Table n. All mating indices for the Aroclor 1260 treated animals seen in the experiment are considered to be normal for the mouse strain employed. Positive control animals had a low mating index for the first week post treatment. ' } *-!T A - v- 0365755-OS - ^^ go.* TOXSTUDIES1918 $*tL*d*ial B I 0 T I S T JaUtaknu, jmo. TABLE II . TEST MATERIAL; Aroclor 1260 Mutagenic Study - Albino Mice Mating Performance Test Week Group Number Number of Surviving Males Number of Animals Precnant Number of Females Mated Mating Index (Percent) C, 2 3 4 5 6 12 12 12 12 12 12 25/36 28/36 31/36 29/36 28/36 29/36 69.4 77.8 86. 1 80.6 77.8 80.6 PC 1 2 3_ 4 S 6 n n n 10 10 10 14/33 19/33 23/33 26/30 23/30 24/30 ' 42.4 57.6 69.7 86.7 76. 7 80.0 #1 .09 03< TOXSTUDIES1919 jUntod BIO-TEST TABLE II continued TEST MATERIAL! Aroclor 1260 Mutagenic Study - Albino Mice Mating Performance Group Teat Week Number Number of Surviving Males Number of Animals Precnant Number of Females Mated Mating Index (Percent) T-I 1 2 3 4 5 6 12 12 12 11 11 1 31/36 31/36 26 /36 28/33 29/33 32/33 86.1 86. 1 72.2 84.8 87.9 97.0 T-II I 2 _3 4 5 6 12 12 12 12 12 12 30/36 30/36 25/36 31/36 27/36 28/36 83.3 83.3 69.4 86. 1 75.0 77.8 1 r. - r? I A A TOXSTUDIES1920 T0XSTUDIES1921 & $ Group Test Week Number Ci 2 3 4 S 6 PC 1 2 3 4 5 6 TABLE III TEST MATERIAL: Aroclor 1260 Mutagenic Study - Albino Mice Pregnant Animals Examined 26 28 31* 29 28 29 14 19 23 26 23 24 Summary of Sacrifice Data -i------------------------ Calculated Corpora Lutea Implantation Sites Resorption Sites Early Late 338 378 417 392 378 392 293 (11.7) 355 (12.7) 342 (11.0) 357 (12.3) 341 (12.2) 349 (12.0) 5 (0.2) 9 (0. 3) 14 (0.4) 15 (0. 5) 13 (0.5) 12 (0.4) 1 (0. 1) 0 (0.0) 5 (0.2) 5 (0.2) 3 (0. 1) 3 (0. 1) 189 256 310 351 310 324 134 (9.6) 178 ( 9.4) 294 (12.8) 334 (12.8) 291 (12.6) 292 (12. 2) ' 41 (2.9) 47 (2.5) 13 (0.6) 16 (0.6) 14 (0.6) 17 (0.7) 2 (0.1) 0 (0.0) 3 (0. 1) 4 (0.2) 5 (0.2) 2 (0. I) Embryos 287 (11.5) 346 (12.4) 323 (10.4) 337 (11.6) 325 (11.6) 334 (11.5) 91 ( 6.5) 131 ( 6.9) 278 (12. 1) 314 (12. 1} 272 (11.8) 273 (11.4) Note: Numbers in parentheses are the means per female. * Includes 1 pseudo-pregnant female (corpora lutea only!. T0XSTUDIES1922 . Tw." ,w I .*. Mkk.r.. P?;: m ' jj* , % EXSEKSEE3ESE3| 9 Grouo Test Week Number ` T-l 1 2 3 4 5 6 T-II 1 2 3 4 5 6 TABLE III continued TEST MATERIAL: Aroc lor 1260 Mutagenic Study - Albino Mice Summary of Sacrifice Data Pregnant Animals Examined 31 31 26* 28 29 32 30 30 25 31 27 28 Calculated Implantation Corpora Lulea Sites 418 339 (10.9) 418 384 (12.4) 349 314 (12.1) 378 335 (12.0) 392 381 (13.1) 432 398 (12.4) 405 342 (11.4) 405 371 (12.4) 338 312 (12.5) 418 376 (12.1) 364 330 (12.2) 378 349 (12.5) Resorption Sites 13 (0.4) 7 (0. 2) 7 (0. 3) 11 (0.4) 14 (0.5) 14 (0.4) i (0.1) 2 (0. 1) 2 (0. I) 5 (0. 2) 1 (0. 1) 4 (0. 1) 13 (0.4) 15 (0.5) 15 (0.6) 16 (0.5) 18 (0.7) 13 (0.5) 1 (0. 1) 2 (0. 1) 4 (0.2) 3 (0. 1) 1 (0. 1) i (0.1) 325 (10.5) 375 (12. 1) 305 (11.7) 319 (11.4) 366 (12.6) 380 (11.9) 328 (10.9) 354 (11.8) 293 (11.7) 357 (11.5) 311 (11.5) 335 (12.0) * Note: Numbers in parentheses are the means per female. * Includes 1 pseudo-pregnant female (corpora lutes only). :3: i/i: 0 3 6 5 7 5 5 .1 3 TOXSTUDIES1923 Another way of expressing the mutation rate, which takes into account pre-implantation losses, is by comparing the mean number of normal embryos in each test group to the mean number of embryos in the control group. inn / Embryos Test Group/Female . _ * ' Embryos Control Croup/Female * ' (B in table) -- Values presented were obtained by comparing each group to the contem porary control group (a) and to cumulative control data (b). Values with a minus (-) sign indicate that the mean number of embryos for that group and week was greater than that of controls. The deviation from sero should not exceed 25 percent in the positive direction. 0365755.U TOXSTUDIES1924 T0XSTUDIES1925 T0XSTUDIES1926 Croup T-r T-U Test Week Number 1 2 3 4 5 6 1 2 3 4 5 6 Pre-Implantation Los s and Mutation Rates Pre-Implantation Loss (Percent) A Mutation Rates B ab IS. 9 8. 1 10.0 n.4 2.8 7.9 3.8 8.7 7.9 1.8 2.4 -8.0 2.2 12, 5 -0.9 3.3 1.7 0.9 3.7 - 8.8 -7.7 3.5 - 3.5 -1.7 15, 6 8.4 7. 7 10. 0 9.3 7. 7 3.8 4. 0 4. 8 4.2 5.4 3.7 5.2 4.8 -11.5 0.9 0.9 - 4.3 4.4 -5.4 -0.9 0.0 1.7 -2.5 T0XSTUDIES1927