Gender Specific Influence of Fish Oil or Atorvastatin on FunctionalProperties of Renal Na,K-ATPase in Healthy Wistar and Hypertriglyceridemic Rats

摘要

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 K_(Na) 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 K_(Na) 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 K_(Na). 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.