[The participation of L-arginine in correcting the activity of the membrane-transport enzymes Na+,K(+)-, Ca2(+)- and Na(+)-ATPases in experimental hypercholesterolemia]. / Uchast' L-arhininu v korektsiï aktyvnosti membrannykh transportnykh fermentiv Na+,K(+)-, Ca2(+)- ta Na(+)-ATFaz za umov eksperimentalnoï hiperkholesterynemiï.

The influence of precursor of biosynthesis of nitric oxide L-arginine on the level of transport enzymes Na+, K(+)-, Ca(2+)- and Na(+)-ATPases activity under rabbits experimental hypercholesterolemia have been studied. The significant changes in Na+, K(+)-, Ca(2+)- and Na(+)-ATPases activity in different tissues (the cortex of kidney, the endothelium of aorta, the epithelium of small intestine, the liver) had been found for the rabbits with inhibition of the activity of this enzymes to the different levels in all these tissues. Injection of L-arginine during the hypercholesterolemia caused the recovery of Na+, K(+)-, Ca(2+)- and Na(+)-ATPases approximately to the control levels. Obtained results demonstrate that exogenous L-arginine may participate in the correction of the activity of membrane transport enzymes under the condition of the rabbits experimental hypercholesterolemia. The authors discuss the possible mechanisms of L-arginine effect on the studied transport enzymes under the experimental atherosclerosis.

[Effect of hypoosmotic stimulation of the gastrointestinal mucosa on the activity of NA+, K+-atpase of epithelial cells in the small intestine and kidney in rats]. / Vplyv giposmotychnoi stymuliatsii slyzovoi poverkhni shlunkovo- kyshkovogo traktu na aktyvnist Na+, K+- ATFazy v klitynakh epiteliiu tonkoi kyshky ta nyrok shchuriv.

The experiments on Wistar rats have shown that intragestral injection with mannitol hypotonic solution (20 mmol/l) causes the significant activation of Na+, K(+)-ATPase of duodenum and distal intestine epithelial cells, kidney cortex cells, but does not affect the brain cortex of Na+, K(+)-ATPase activity. Simultaneously the activator of enzyme (AE) enters blood serum of rats, its activity is revealed by blood serum addition to homogenates of tissues of control rats. It is assumed that AE is produced in duodenal and intestinal mucosa released to blood after stimulation of mucosal surface by hypotonic solutions and included into the osmoregulation processes on the Na+, K(+)-ATPase level.

[Secretion of endogenous regulators of Na K ATPase by isolated rat duodenum in osmotic stimulation of its mucous membrane]. / Sekretsiia endohennykh reguliatoriv Na+, K+-ATFazy izol'ovanoiu dvanadtsaiatypaloiu kyshkoiu shchuriv pid vplyvom osmotychnoï stymuliatsiï ïï slizovoï obolochki.

The experiments in vitro have shown that perfusion of the isolated duodenum cavity in rats by hypotonic (20 mosmol/l H2O) or hypertonic (500 mosmol/l H2O) solutions of NaCl and mannitol during 10 min stimulates secretion of endogenic factors (activators or inhibitors of enterocytes of Na+, K(+)-ATPase) into the serous incubation solution. Contact of the duodenum mucose surface with isotonic (300 mosmol/l H2O) solutions does not stimulate the secretion of this enzyme regulators. Endogenic substance are thermostable: they retain activity relative to Na+, K+ ATPase of enterocytes after heating (100 degrees C, 10 min duration) of serous incubation solutions.