Induction of kinetochore positive and negative micronuclei in mouse bone marrow cells by salicylazosulfapyridine and sulfapyridine.

Salicylazosulfapyridine (SASP) and its major metabolite sulfapyridine (SP) have been shown to induce chromosomal damage in vivo. Both chemicals were tested in the micronucleus (MN)/kinetochore (KC) staining test to gain insight into the question of whether chromosomal breakage, aneuploidy-inducing events, or both were important to the observed production of MN in bone marrow cells of mice. In this test, both SASP and SP were shown to be strong inducers of kinetochore positive (KC+) MN. Although small increases in kinetochore negative (KC-) MN were also observed in SP treated mice, as well as in mice receiving the highest dose of SASP tested, the results suggest that both chemicals induce predominantly aneuploidogenic type damage.