Triethylenemelamine induced dominant lethals in mice--comparisons of oral versus intraperitoneal injection

We have compared the relative effectiveness of oral and i.p. injections of triethylenemelamine (TEM) in inducing dominant lethality in male mice. The standard dominant lethal protocol was used in these experiments. TEM, when injected i.p. resulted in significant increased in fetal mortality during the first three weeks post-treatment. Decreases in the number of implants per pregnant female were noted during this same period, with only minor decreases in fertility. In contrast, oral injections of TEM resulted in only fluctuations in the percent of fetal mortality. In addition, oral injections of TEM did not result in significant differences in either total implants or percent fertility. Possible causes of the observed differences between these two routes of administration are discussed.