Effects of chronic and acute ethanol exposure on renal (Na + K)-ATPase in the rat.
1. We evaluated the effects of chronic ethanol consumption on the kinetic properties of renal (Na + K)-ATPase and compared them with acute inhibition by ethanol in vitro. 2. When adult rats were fed 20% ethanol for 10 weeks, renal (Na + K)-ATPase activity increased but the sensitivity of the enzyme to ethanol inhibition in vitro was not altered. 3. Vmax was increased by ethanol consumption, whereas K0.5 and nH were not changed. The kinetic parameters of Mg(2+)-ATPase were not affected under the same conditions. 4. We concluded that ethanol-induced tolerance or enhancement of renal (Na + K)-ATPase or both can be explained on the basis of an increase in Vmax.
Rodrigo
R
R
Departamento de Medicina Experimental, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
Thielemann
L
L
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D000431:Ethanol / Q000494:pharmacology*; D005260:Female; D007668:Kidney / Q000187:drug effects / Q000201:enzymology*; D007672:Kidney Cortex / Q000187:drug effects / Q000201:enzymology; D007679:Kidney Medulla / Q000187:drug effects / Q000201:enzymology; D007700:Kinetics; D008861:Microsomes / Q000187:drug effects / Q000201:enzymology; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*
D002492:Central Nervous System Depressants; D000431:Ethanol; D000255:Adenosine Triphosphate; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium