For better understanding of pathophysiological processes leading to increased retention of sodium as a consequence of hyperlipidemia, the properties of renal Na,K-ATPase, a key enzyme involved in maintaining sodium homeostasis in the organism, were studied. Enzyme kinetics of renal Na,K-ATPase were used for characterization of ATP- and Na+-binding sites after administration of fish oil (FO) (30 mg·day-1) or atorvastatin (0.5 mg·100 g-1·day-1) to healthy Wistar rats and rats with hereditary hypertriglyceridemia of both genders. Untreated healthy Wistar and also hypertriglyceridemic female rats revealed higher Na,K-ATPase activity as compared to respective untreated male groups. Hypertriglyceridemia itself was accompanied with higher Na,KATPase activity in both genders. Fish oil improved the enzyme affinity to ATP and Na+, as indicated by lowered values of Km and KNa in Wistar female rats. In Wistar male rats FO deteriorated the enzyme in the vicinity of the Na+-binding site as revealed from the increased KNa value. In hypertriglyceridemic rats FO induced a significant effect only in females in the vicinity of the sodium binding sites resulting in improved affinity as documented by the lower value of KNa. Atorvastatin aggravated the properties of Na,KATPase in both genders of Wistar rats. In hypertriglyceridemic rats protection of Na,K-ATPase was observed, but this effect was bound to females only. Both treatments protected renal Na,K-ATPase in a gender specific mode, resulting probably in improved extrusion of excessive intracellular sodium out of the cell affecting thus the retention of sodium in hHTG females only.
- MeSH
- adenosintrifosfát metabolismus MeSH
- anticholesteremika MeSH
- hypertriglyceridemie farmakoterapie metabolismus MeSH
- inbrední kmeny potkanů MeSH
- krysa rodu rattus MeSH
- kyseliny heptylové farmakologie MeSH
- ledviny enzymologie metabolismus MeSH
- potkani Wistar MeSH
- pyrroly farmakologie MeSH
- rybí oleje farmakologie terapeutické užití MeSH
- sexuální faktory MeSH
- sodíko-draslíková ATPasa metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
The present study was focused on regulatory role of nitric oxide on functional properties of the cardiac Na, K-ATPase in three various animal models of hypertension: spontaneously hypertensive male rats (SHR) with increased activity of nitric oxide synthase (NOS) by 60 % (Sh1), SHR with decreased activity of NOS by 40 % (Sh2) and rats with hypertension induced by L-NAME (40 mg/kg/day) with depressed activity of NOS by 72 % (LN). Studying the utilization of energy substrate we observed higher Na, K-ATPase activity in the whole concentration range of ATP in Sh1 and decreased activity in Sh2 and LN. Evaluation of kinetic parameters revealed an increase of Vmax value by 37 % in Sh1 and decrease by 30 % in Sh2 and 17 % in LN. The KM value remained unchanged in Sh2 and LN, but was lower by 38 % in Sh1 indicating increased affinity of the ATP binding site, as compared to controls. During the activation with Na+ we observed increased Vmax by 64 % and increased KNa by 106 % in Sh1. In Sh2 we found decreased Vmax by 40 % and increased KNa by 38 %. In LN, the enzyme showed unchanged Vmax with increased KNa by 50 %. The above data indicate a positive role of increased activity of NOS in improved utilization of ATP as well as enhanced binding of Na+ by the cardiac Na, K-ATPase.
- MeSH
- adenosintrifosfát metabolismus MeSH
- chlorid sodný metabolismus MeSH
- energetický metabolismus MeSH
- hypertenze chemicky indukované enzymologie genetika patofyziologie MeSH
- inhibitory enzymů MeSH
- kinetika MeSH
- krevní tlak MeSH
- krysa rodu rattus MeSH
- modely nemocí na zvířatech MeSH
- myokard enzymologie MeSH
- NG-nitroargininmethylester MeSH
- oxid dusnatý metabolismus MeSH
- potkani inbrední SHR MeSH
- sodíko-draslíková ATPasa metabolismus MeSH
- synthasa oxidu dusnatého antagonisté a inhibitory metabolismus MeSH
- vazebná místa MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
