Effects of phenobarbital and rose bengal on the ATPases of plasma membranes of rat and rabbit liver

Stimulation of hepatic sodium and potassium-activated adenosine triphosphatase activity by phenobarbital. Its possible role in regulation of bile flow.

“…In contrast to findings of previous studies (68)(69)(70), administration of phenobarbital significantly increased (Na+-K+)-ATPase activity almost twofold in liver surface membrane fractions. Increased (Na+-K+)-ATPase is not due to isolation of different surface membrane fractions in the treated animals, as shown by the threefold increase in total liver homogenates (Na+-K+)-ATPase activity and the uinaltered recovery of surface membrane protein and relative enrichement of membrane marker enzymes (Table II).…”

Relationship between bile flow and Na+, K+-adenosinetriphosphatase in liver plasma membranes enriched in bile canaliculi.

“…The normal values for Na+,K+-ATPase in the present experiments are about three times higher than those reported by other workers (3,4,23). This could have resulted from the higher gravitational field which may have led to the precipitation of particles enriched in ATPase into the LPM fraction.…”

“…Some of these discrepancies may be due to differences in methodology. Thus, Laperche Na+,K+-Adenosinetriphosphatase Activity and Bile Flowet al (23) collected the surface membranes at the density 1.17-1.20 interface using a zonal rotor, whereas in the present investigation the LPM fraction was recovered at the density 1.16-1.18 interface. Simon and Sutherland (31), using Neville's procedure (32) which is similar to that of Song et al (9), described a clear-cut increase in canalicular Na+,K+-ATPase activity.…”

“…Several drugs and hormones, such as ethinyl estradiol (5,27), rose bengal (23,28), and icterogenin (29) (23,30,31). Some of these discrepancies may be due to differences in methodology.…”

Studies of Relationships among Bile Flow, Liver Plasma Membrane NaK-ATPase, and Membrane Microviscosity in the Rat

“…For example, phenobarbital treatment also has been associated with either no change (10)(11)(12) or a decrease (13) in LPM NaK-ATPase activity, and dexa-I Abbreviations used in this paper: BAIF, bile acidindependent flow; LPM, isolated liver plasma membrane. methasone has been shown to decrease BAIF while increasing NaK-ATPase activity (14).…”