Stimulation of NADH oxidase activity from rat liver plasma membranes by growth factors and hormones is decreased or absent with hepatoma plasma membranes.
Plasma membranes of rat liver isolated by aqueous two-phase partition exhibited basal levels of NADH oxidase activity that were increased approx. 2-fold by addition of hormones and growth factors to which liver cells were known to respond. In contrast, hepatoma plasma membranes demonstrated an intrinsically increased level of NADH oxidase, which was not stimulated further by addition of growth factors. The results suggest that the NADH oxidase of the hepatoma plasma membrane is no longer correctly coupled to hormone and growth-factor receptors. This biochemical defect may parallel the loss of growth control that is characteristic of neoplastic transformation in hepatocarcinogenesis and other transformation systems.
Bruno
M
M
Department of Medicinal Chemistry, Purdue University, West Lafayette, IN 47907.
Brightman
A O
AO
Lawrence
J
J
Werderitsh
D
D
Morré
D M
DM
Morre
D J
DJ
D000818:Animals; D002462:Cell Membrane / Q000201:enzymology / Q000648:ultrastructure; D002469:Cell Separation; D004052:Diethylnitrosamine; D004815:Epidermal Growth Factor / Q000494:pharmacology; D005934:Glucagon / Q000494:pharmacology; D006133:Growth Substances / Q000494:pharmacology*; D006728:Hormones / Q000494:pharmacology*; D007328:Insulin / Q000494:pharmacology; D007700:Kinetics; D007781:Lactoferrin / Q000494:pharmacology; D008099:Liver / Q000201:enzymology* / Q000648:ultrastructure; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced / Q000201:enzymology* / Q000648:ultrastructure; D008297:Male; D009097:Multienzyme Complexes / Q000378:metabolism*; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism*; D051381:Rats; D011916:Rats, Inbred F344; D014667:Vasopressins / Q000494:pharmacology
D006133:Growth Substances; D006728:Hormones; D007328:Insulin; D009097:Multienzyme Complexes; D014667:Vasopressins; D004052:Diethylnitrosamine; D004815:Epidermal Growth Factor; D005934:Glucagon; C023107:NADH oxidase; D009247:NADH, NADPH Oxidoreductases; D007781:Lactoferrin