Gamma glutamyl transpeptidase as a sensitive marker of fetal alcohol exposure.

Changes in gamma-glutamyl transpeptidase (gamma-GTP) activity have been shown to occur concomitantly with ethanol use. Alterations in gamma-GTP isozymal forms have also been demonstrated to accompany various developmental stages, diseases, and drug exposures. In view of these properties, electrophoretic examination of gamma-GTP isozymal forms was performed on sera from neonatal rats exposed to ethanol during gestation. The purpose of this study was to see whether or not a form of the enzyme specific for prenatal ethanol exposure could be demonstrated. Pregnant Wistar rats were pair-fed on diets containing either ethanol (1, 4, 5, or 6.7% v/v) or diets without ethanol which were isocalorically equivalent. Sera collected from one day old neonates were separated into gamma-GTP fractions using polyacrylamide gradient gel electrophoresis. The zymograms were specifically stained for gamma-GTP activity and desitometrically scanned. All alcohol groups had 4 bands of gamma-GTP activity shared in common with the control groups. However, in addition to these bands the sera from the neonates exposed to ethanol in utero were found to have a unique band of gamma-GTP activity. This unique band was present in all zymograms of sera from ethanol-exposed neonates and absent in all control neonates. The possibility therefore exists that gamma-GTP serum isozymes may be useful as a diagnostic index available for the assessment of Fetal alcohol exposure in man.