Multilaboratory comparison of in vitro tests for chromosome aberrations in CHO and CHL cells tested under the same protocols

✍ Scribed by Sheila M. Galloway; Toshio Sofuni; Michael D. Shelby; A. Thilagar; V. Kumaroo; Parvinder Kaur; Dushant Gulati; Donald L. Putman; Hemalatha Murli; Richard Marshall; Noriho Tanaka; B. Anderson; Errol Zeiger; Motoi Ishidate Jr.

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 511 KB
• Volume: 29
• Category: Article
• ISSN: 0893-6692
• DOI: 10.1002/(sici)1098-2280(1997)29:2<189::aid-em10>3.0.co;2-a

✦ Synopsis

Different test results have been reported for the same were obtained in both cell types, CHL cells sometimes chemicals in two in vitro chromosome aberration had higher aberration levels and survived at higher test systems, CHL cells tested by a Japanese protocol doses than CHO cells would tolerate. This may reflect and CHO cells tested by the US National Toxicol-some intrinsic difference in sensitivity but may also be ogy Program [Sofuni et al., Mutat Res 241:173 -affected by factors such as cell cycle length and culture 213,1990]. Here, laboratories in Japan, the US media (e.g., oxygen scavenging capacity). The collaboand the UK tested 9 such chemicals in CHL and ration reported here also contributed to a better under-CHO cells using the same protocols and found all standing of scoring aberrations, especially ''gaps''; 9 positive in both cell types; differences in earlier there was good agreement on what types of aberrations conclusions with these chemicals were due mainly should be included in the totals when scoring criteria to test protocol, not to different sensitivities of the were clearly defined, for example, many changes classicells. The most important protocol difference is sam-fied as ''gaps'' by the Japanese system were classified pling time. Chemicals that were negative in the NTP as ''breaks'' in the scoring systems used in the United series using a sampling time of 10 to 13 hours often

States and the United Kingdom, and were appropriately produced positive results when retested here with a included in total aberration counts. Environ. Mol. Muta-20-to 24-hour sampling time. While positive results gen 29: 189-207, 1997.