Alteration by phenobarbital of membrane-associated enzymes including gamma glutamyl transpeptidase in mouse liver neoplasms.
Administration of phenobarbital for 5 to 7.5 weeks to aged C3HfB/HeN mice with spontaneous liver tumors produced an enhancement of gamma glutamyl transpeptidase activity in the tumors and a decrease in glucose-6-phosphatase and adenosine triphosphatase activity. Discontinuation of phenobarbital feeding for 5.5 weeks resulted in the loss of gamma glutamyl transpeptidase activity in tumors. These findings of alterations in three membrane-associated enzymes indicate that phenobarbital produces substantial changes in the composition of cellular membranes which may be related to its promoting activity.
Williams
G M
GM
Naylor Dana Institute for Disease Prevention, American Health Foundation, Valhalla, NY 10595, USA.
Ohmori
T
T
Katayama
S
S
Rice
J M
JM
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000201:enzymology; D005260:Female; D005952:Glucose-6-Phosphatase / Q000378:metabolism; D008114:Liver Neoplasms, Experimental / Q000201:enzymology*; D008297:Male; D051379:Mice; D010634:Phenobarbital / Q000494:pharmacology*; D005723:gamma-Glutamyltransferase / Q000378:metabolism*
D005723:gamma-Glutamyltransferase; D005952:Glucose-6-Phosphatase; D000251:Adenosine Triphosphatases; D010634:Phenobarbital