Evaluation of the teratogenicity of ethylenediamine dihydrochloride in Fischer 344 rats by conventional and pair-feeding studies.

Ethylenediamine dihydrochloride (EDA.2HCl) was fed to groups of 20 (40 controls) timed-pregnant rats on Gestation Days 6 through 15 at 1.0, 0.25, 0.05, or 0 g/kg/day. The day of discovery of a vaginal plug was considered gestation day 0. On Gestation Day 21, the fetuses were delivered by cesarean section, and the standard endpoints for teratogenicity were evaluated. At 1.0 and 0.25 g/kg/day, reductions in maternal diet consumption and weight gain were observed during the exposure period. At 1.0 g/kg/day, fetal weight and crown-rump length were significantly reduced and the percentage of litters with resorptions, with skeletal variants, and with missing or shortened innominate arteries was increased. To circumvent the possible problem of palatability of the diet and/or the effects of reduced food intake, a probe study was performed in which 1.0 or 0 g/kg/day was given to pregnant rats by gavage on Gestation Days 6 through 15. However, food intake was also substantially reduced with gavage dosing of the test substance. To determine whether the arterial defects were the result of reduced food intake, a pair-feeding study was performed in which EDA.2HCl was fed on Gestation Days 6 through 15 at 1.0 g/kg/day. A pair-fed control group received the same amount of diet consumed by the EDA.2HCl-treated rats. An untreated control group was fed ad libitum. All groups contained 20 pregnant females. Maternal weight gain, fetal weight and length, and the length of the innominate artery were all reduced in the EDA.2HCl-treated group compared to both control groups. Two fetuses each in the EDA.2HCl-treated and pair-fed control groups had missing innominate arteries versus none in the untreated controls. The four affected fetuses were from four different litters. Ingestion of EDA.2HCl resulted in reduced maternal weight gain, fetal size, and length of the innominate artery, but the missing innominate artery was not a result of EDA.2HCl treatment. Therefore, there was no evidence of teratogenicity in Fischer 344 rats from EDA.2HCl ingestion during organogenesis.

Chronic toxicity and oncogenicity studies of ethylene glycol in rats and mice.

These studies were performed to assess the chronic toxicity and oncogenicity of ethylene glycol (EG) in rats and mice. Groups of 130 Fischer 344 rats and 80 CD-1 mice per sex were fed diets yielding approximate dosages of 1.0, 0.2, or 0.04 g/kg/day of EG. Two separate control groups in each study received no EG. Mortality rate was increased in high-dose male rats all of which died by 475 days. The following effects were also observed in high dose male rats: reduced body weight gain, increased water intake, increased blood urea nitrogen and creatinine, reduced erythrocyte count, reduced hematocrit and hemoglobin, increased neutrophil count, increased urine volume, reduced specific gravity and pH. Urinary calcium oxalate crystals and increased kidney weight were seen in all high-dose rats. Uric acid crystals were seen in the urine of high-dose female rats at 18 and 24 months. Histopathologic changes in high-dose male rats included tubular cell hyperplasia, tubular dilation, peritubular nephritis, parathyroid hyperplasia, and generalized soft tissue mineralization. Fatty change of the liver was seen in high- and intermediate-dose female rats. No clinical signs, or gross or microscopic evidence of toxicity was seen in mice at the dosages used. Water intake and clinical pathologic parameters were not measured in the mouse study. In these studies there was no evidence of an oncogenic effect of EG in rodents.

Three-generation reproduction and dominant lethal mutagenesis studies of ethylene glycol in the rat.

To assess the possible effects of ethylene glycol (EG) on reproductive performance and mutagenesis, three-generation reproduction and dominant lethal mutagenesis studies were performed in the Fischer 344 rat. EG was included in the diet at approximate dosages of 1.0, 0.2, and 0.04 g/kg/day during three generations of reproduction. Each generation was bred once. In a dominant lethal mutagenesis study, the F2 males from the reproduction study were bred to three consecutive lots of untreated females at weekly intervals. Concomitantly, another group of untreated F2 males that received a single ip injection of 0.50 mg/kg triethylenemelamine (TEM) were bred similarly to serve as a positive control group. No evidence of reduced fertility or increased fetal death was observed in any of the groups receiving EG. Dominant lethal effects in the TEM group confirmed the susceptibility of the rats to a known mutagen. In conclusion, there were no reproductive or dominant lethal effects associated with the inclusion of as much as 1.0 g/kg/day of EG in the diet.

Two-generation reproduction study of ethylenediamine in Fischer 344 rats.

Ethylenediamine dihydrochloride (EDA X 2 HCl) was incorporated in the diet of Fischer 344 rats at dosage goals of 0.50, 0.15, 0.05, or 0 g/kg/day in a two-generation reproduction study. The parent generation (F0) and the F1 generation were each bred once. Parameters examined included indices of fertility, gestation of dams, gestation survival, 0- to 4-, 4- to 14- and 4- to 21-day survival of pups, number of pups born alive, and number of pups weaned per litter. Furthermore, observations were made on mortality, diet consumption, and body weight of the adult rats in F0 and F1 generation. Randomly selected F1 weanlings and adults and F2 weanlings were sacrificed and organ weights were obtained; in addition, gross and histologic examinations were conducted on these rats. No reproductive toxicity was observed in this study. Some effects were observed in both sexes for the F0 and F1 parent rats. These effects were mainly associated with the high dosage level and included reduction of body weight gain and changes in liver (decrease) and kidney (increase) weights in the adult rats. The only microscopic lesion observed was hepatocellular pleomorphism in the high level F1 adult males and females; a greater prevalence and severity of this lesion was seen in the female rats.

Assessment of genotoxic potential of ethylenediamine: in vitro and in vivo studies.

Ethylenediamine (EDA) was evaluated for potential genotoxic activity using a battery in vitro and in vivo mammalian tests. The tests employed were the Chinese hamster ovary (CHO) gene mutation assay, the sister-chromatid exchange (SCE) test with CHO cells, unscheduled DNA synthesis (UDS) assays with primary rat hepatocytes and a dominant lethal study with Fischer 344 rats. EDA did not produce a positive, dose-related, mutagenic effect in either the CHO mutation assay or in the SCE test when evaluated both with and without the addition of a rat-liver S9 activation system. With hepatocytes, no positive effects of EDA upon UDS values were noted in 2 separate studies using either a scintillation counting procedure or an autoradiographic method to determine UDS activity. In a dominant lethal study, male rats fed for 23 weeks with dietary levels of EDA X 2HCl of 0, 0.05, 0.15 or 0.50 g/kg/day, and mated with 1 virgin female/week for 3 consecutive weeks, showed no dose-related or statistically significant effects upon fertility, total number of implantations/female, or the number of living and dead implants per female; marked effects upon the incidence of dominant lethal mutations were noted in the positive control group injected intraperitoneally with one dose of 0.25 mg/kg triethylenemelamine. We conclude that EDA was not genotoxic in the in vitro and in vivo mammalian test systems employed.

Acute and subchronic toxicity of ethylenediamine in laboratory animals.

As part of a comprehensive toxicology program on ethylenediamine (EDA), acute, short-term repeated and subchronic toxicity studies were conducted. Ethylenediamine dihydrochloride (EDA X 2HCl) was used in these studies. EDA X 2HCl was slightly to moderately toxic to laboratory rats, mice or rabbits in the following acute tests: Peroral intubation, percutaneous administration, primary skin irritation and eye injury. Following dietary inclusion of EDA X 2HCl for 7 days at up to 2.70 g/kg/day to Fischer 344 rats or B6C3F1 mice, body weight gain and some organ weights of the animals were depressed in both sexes at the highest dose level. When Fischer 344 rats were fed EDA X 2HCl at 0, 0.05, 0.25, 1.00 g/kg/day for 3 months, marked decreases in body weight gain were observed in both sexes at the highest dose level. Other dose-related effects observed in either or both sexes primarily at the highest dose level, and for some at the intermediate dose level, included organ weight changes and alterations in some clinical chemistry, hematology and urinalysis parameters. No deaths occurred during the exposure period, nor were there any significant gross lesions in any of the animals. Histologic findings indicate a dose-related increase in hepatocellular pleomorphism and mild hepatocellular degeneration.

Subchronic and reproductive toxicology studies on acrylic acid in the drinking water of the rat.

In the subchronic study acrylic acid was incorporated in the drinking water of Fischer 344 rats (15 per group) for three months at dosage levels of 0.75, 0.25, 0.083 or 0 g/kg/day. No deaths occurred during the study but several treatment-related effects were observed. At 0.75 g/kg/day dosage level, body weight gain was reduced as were food and water consumption. Changes in organ weights and clinical chemistry parameters were observed along with increases in urine specific gravity and protein concentration. Similar, though less profound, changes occurred at 0.25 g/kg/day. At 0.083 g/kg/day, the only effect was a reduction of water consumption by male rats. There were no significant treatment-related histopathologic changes. Many of the effects observed may have been the result of decreased water and food consumption rather than specific toxic effects of acrylic acid. In the reproduction study, the same dosages of acrylic acid were given to groups of 10 males and 20 females for 90 days after which the animals were mated. Treatment was continued throughout gestation and lactation. Treatment-related effects included decreased body weight gain, and reduced food and water consumption in F0 rats at the 2 highest dosage levels. Organ weight changes occurred in both F0 and F1 animals and reduced body weight gain was seen in the F1 pups at the highest level. No statistically significant changes in reproductive indices were observed, perhaps because of an atypical control group.

Urinary lactic dehydrogenase and serum C-reactive protein as means of localizing the site of urinary tract infection in patients with ileal conduits.

Many patients with ileal conduit urinary diversion have infected urine but far fewer have clinical pyelonephritis. A noninvasive diagnostic test to distinguish renal bacteriuria from conduit colonization in these patients would seem desirable. Urine total lactic dehydrogenase and lactic dehydrogenase isoenzymes, and serum C-reactive protein have been useful to distinguish pyelonephritis from cystitis in patients with intact urinary tracts. We used these tests in patients with ileal conduits who had urine containing more and less than 10(5) organisms per ml. All patients had elevated urine total lactic dehydrogenase-5 isoenzyme, and serum C-reactive protein. No statistically significant difference in any of these parameters existed between the groups. These results may indicate that all patients with conduits have pyelonephritis but only intermittently demonstrate bacteriuria, or that the conduit mucosa contributes lactic dehydrogenase to the urine. However, it does not appear that these tests alone can distinguish accurately renal bacteriuria from conduit colonization.