title: [Increased brain Na, K-ATPase activity of rats under stress].
abstract: The activities of Na, K- and Mg-dependent ATPases were measured in crude synaptosomal fractions isolated from the rat brain gray matter. Prolonged (6 h) exposure to emotional painful stress stimulated Na, K-ATPase activity by 40% without affecting that of Mg-ATPase. Preliminary injection of the free radical scavenger ionol presented Na, K-ATPase activation, thus suggesting the involvement of lipid peroxidation initiated in brain tissues under stress in acceleration of NA-pump function. However, model studies with lipid peroxidation induced in vitro by an ascorbate-dependent system in a membranous suspension demonstrated an opposite effect, i. e. fast inhibition of Na, K-ATPase. Possible reasons for the different effects of lipid peroxidation in vivo under stress and on Na, K-ATPase activity in vitro are discussed. It is concluded that activation of Na K-ATPase is a mechanism which is responsible for acceleration of reflex conditioning and for the maintenance of the conditioned reflexes in stress-exposed animals.
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000201:enzymology*; D002084:Butylated Hydroxytoluene / Q000494:pharmacology; D017301:Ca(2+) Mg(2+)-ATPase; D006801:Humans; D008054:Lipid Peroxides / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D013315:Stress, Psychological / Q000201:enzymology*
chemical_list: D008054:Lipid Peroxides; D002084:Butylated Hydroxytoluene; D000251:Adenosine Triphosphatases; D017301:Ca(2+) Mg(2+)-ATPase; D000254:Sodium-Potassium-Exchanging ATPase
vernacular_title: Uvelichenie aktivnosti Na, K-ATFazy mozga krys pri stresse.