Testing Information

Descriptions of NTP Study Types

Abstract for Teratology: Glyoxal Trimeric Dihydrate

Print this page Easy Link

http://ntp.niehs.nih.gov/go/12993

Developmental Toxicity of Glyoxal Trimeric Dihydrate, (CAS No. 4405-13-4) in New Zealand White (NZW) Rabbits

NTP Study: TER92121

ABSTRACT

This study was conducted to assess the potential for orally administered glyoxal trimeric dihydrate (GLOX) to cause developmental toxicity. The most common human exposure to GLOX occurs as a result of ingestion of heated foods, in cigarette smoke, and in ozonated drinking water. The lack of pertinent developmental toxicity data in the published literature prompted this study. GLOX was administered by gavage in water to artificially inseminated New Zealand White (NZW) rabbits on gestation days (gd) 6 through 19 at levels of O and 50 mg/kg/day. Only the 50 mg/kg/day dose level was used in an effort to ensure some maternal toxicity while avoiding the severe toxicity observed at higher doses (National Toxicology Program, unpublished results). If notable developmental effects had been observed at this maternally toxic dose, lower doses would have been tested. Animals were observed daily for clinical signs and weighed on the mornings of gd 0, 3, 6 through 19, 25, and 30. Food weights were recorded for the animals in each group on gd 0, 3, 6, 9, 12, 15, 18, 19, 22, 25, 28, and 30. All animals were killed on gd 30 and examined for maternal body and organ weights, implant status, fetal weight, sex, and morphological development.

There was no maternal mortality during the study and there was no treatment-related increase in the incidence of clinical signs. Maternal absolute and relative (g/kg body weight) food consumption were suppressed during the periods of gd 6 to 12, gd 15 to 19, and gd 6 to 19 (during dosing), but food consumption returned to control levels after the end of dosing. Body weight change was significantly reduced in the GLOX-treated animals during the period of gd 6 to 9, but no other effects on maternal body weight were observed. Necropsy of maternal animals revealed no treatment-related effect on maternal liver weight. GLOX exposure did not significantly alter post-implantation loss. GLOX had no effect on fetal body weight, or the incidence of external, visceral, or skeletal malformations.

In summary, maternal toxicity was manifested only as a transient reduction in body weight and food consumption at 50 mg/kg/day during the treatment period. No clear-cut evidence of developmental toxicity was observed at 50 mg/kg/day in the presence of mild maternal toxicity. This study suggests a NOAEL for maternal effects of ~50 mg/kg/day GLOX and a NOAEL of 50 mg/kg/day GLOX for developmental toxicity administered by gavage to pregnant NZW rabbits during organogenesis.

Report Date: August 1993

NTIS# PB94-104064


Return to Organ Systems Toxicity Abstracts