Reduction of all-trans-retinoic acid-induced teratogenesis in the rat by glycine administration.
BACKGROUND
Prenatal rat embryo exposure to retinoids induces severe malformations in various organs; the most active and teratogenic metabolite is all-trans-retinoic acid (atRA). The mechanisms of this embryopathy are only partly known. In the present study, the influence of glycine on the teratogenicity of atRA was investigated.


METHODS
Embryos from 5 groups of white rats were studied: Group 1 remained untreated; Group 2 received glycine 2% in drinking water ad libitum from the first gestational day (GD 1); Group 3 was administered vehicle (corn oil); Group 4 was treated with atRA (50 mg/kg of body weight) injected (IP); and Group 5 was treated with atRA (50 mg/kg of body weight IP) plus glycine 2% in drinking water ad libitum from GD 1. atRA was administrated daily from GD 8-10. Dams were killed on the 21st day of pregnancy, and their fetuses were examined to detect external, visceral, and skeletal malformations.


RESULTS
The results show that the atRA-administered dose is not toxic for the dams, and that although fetal death was not observed, it produced abnormalities in the fetuses. Glycine reduced atRA-induced teratogenic effects (external and skeletal defects).


CONCLUSIONS
The results indicate that glycine effectively reduces the teratogenic effects of atRA. Thus, glycine might be useful for the prevention of vitamin A teratogenicity.
Martínez-Angoa
Alba
A
Department of Genetics, National Institute of Respiratory Diseases, México, Distrito Federal.
Parra-Hernández
Elías
E
Madrigal-Bujaidar
Eduardo
E
Chamorro-Cevallos
Germán
G
Carvajal-Sandoval
Guillermo
G
Zamudio-Cortes
Pedro
P
D000014:Abnormalities, Drug-Induced / Q000517:prevention & control*; D000818:Animals; D000970:Antineoplastic Agents / Q000633:toxicity*; D004336:Drug Antagonism; D005260:Female; D005313:Fetal Death / Q000139:chemically induced / Q000517:prevention & control; D005998:Glycine / Q000494:pharmacology*; D018684:Glycine Agents / Q000494:pharmacology*; D008431:Maternal-Fetal Exchange / Q000187:drug effects; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D013723:Teratogens / Q000633:toxicity*; D014212:Tretinoin / Q000633:toxicity*
D000970:Antineoplastic Agents; D018684:Glycine Agents; D013723:Teratogens; D014212:Tretinoin; D005998:Glycine