Prenatal interactions between ethanol and the industrial solvent 2-ethoxyethanol in rats: neurochemical effects in the offspring
Nelson, B.K.; Brightwell, W.S.; Setzer, J.V.; O'Donohue, T.L.
Neurobehavioral Toxicology and Teratology 4(3): 395-401
1982
ISSN/ISBN: 0275-1380 PMID: 6124892 Document Number: 193154
Behavioral and neurochemical deviations in the offspring of rats exposed to 100 ppm ethoxyethanol during gestation have been previously reported. Since the metabolism of this compound could speculatively be similar to that of ethanol, the present study investigated the interactive effects of ethanol and ethoxyethanol on prenatal developments. Groups of 15-20 pregnant Sprague-Dawley rats were given 10% ethanol in the drinking water with or without concomitant inhalation exposure to 100 ppm ethoxyethanol during gestation days 7-13 or 14-20. As a positive control, another group was exposed to 200 ppm ethoxyethanol on gestation days 7-13; sham-exposed controls were included for both gestation periods. Ten to 15 pups per group were sacrificed by focused microwave irradiation either on the day of birth (whole-brain assays) or at 21 days (regional assay). Using radioenzymatic techniques, samples were assayed for steady state levels of protein, acetylcholine, dopamine, 5-hydroxytryptamine and norepinephrine. Ethanol alone had minimal effects, with only 1 deviation from controls resulting from administration on days 7-13, and 3 deviations in newborn pups from administration on days 14-20. Combined exposure to ethanol and ethoxyethanol on days 7-13 resulted in only 1/3 the number of deviations as had been previously observed after ethoxyethanol alone. In contrast, combined exposure to ethanol and ethoxyethanol on days 14-20 resulted in nearly twice as many deviations as had been observed after ethoxyethanol alone. Administration of ethanol early in gestation of rats may reduce the effects, but later in gestation may enhance the prenatal effects of ethoxyethanol.