ABSTRACT
The effect of subchronic feeding of immobilized lactase composite following in utero exposure was studied in Sprague-Dawley rats. The dose levels of immobilized lactase composite that were used were 25, 100 and 400 mg per kg body weight per day. Reproduction performance, body weight gain and food consumption, organ weight, hematological and clinical chemical data, and ophthalmic, gross and histopathological examinations were used to study possible toxicological or pathological effects. No treatment-related effects were observed in either male or female rats exposed to immobilized lactase composite at any dose level.
Subject(s)
Enzymes, Immobilized/toxicity , Galactosidases/toxicity , beta-Galactosidase/toxicity , Animals , Body Weight/drug effects , Female , Fertility/drug effects , Food , Hematologic Tests , Male , Organ Size , Pregnancy , Rats , Time FactorsSubject(s)
Cellulase/toxicity , Galactosidases/toxicity , Acute Disease , Animals , Chronic Disease , RatsABSTRACT
Twelve human uteri containing intrauterine contraceptive devices (IUDs) and ten uteri without IUDs were obtained at hysterectomy. Samples of fluid were collected from the uterine lumina by absorbing the fluid in small pieces of lens paper. In the samples of luminal fluid we measured the concentration of beta-galactosidase, an enzyme which is present in human neutrophilic leukocytes and whose concentration in luminal fluid should correlate with the local inflammatory response to the intrauterine foreign body. In the samples of fluid from IUD-bearing uteri, the concentration of beta-galactosidase was significantly (P less than 0.0005) greater than that in luminal fluid from control uteri, the averages of the two groups differing by 3.8 units. To determine whether a foreign-body response of this magnitude could have any effect on preimplantation embryos, we cultured mouse embryos from day 4 to day 7 of development in culture media to which extracts of human leukocytes were added. All mouse embryos were killed when the culture media contained enough leukocyte extract to give beta-galactosidase concentrations of 0.5 unit or higher. Thus mouse embryos were killed by leukocyte extracts whose beta-galactosidase concentrations were actually less than the concentration of this marker enzyme measured in IUD uterine fluid. This comparison indicates that the luminal fluid in IUD-bearing uteri contains leukocyte break-down products in sufficient concentration to be lethal for preimplantation embryos.
