homocysteine thiolactone was demonstrated to inhibit the growth of 10–12-day-old chicken embryo cardiac tissue explants at 7 × 10−9 −1 × 10−3 m concentrations in a dose-dependent manner. the maximal cardiotoxic effect of homocysteine thiolactone was detected at 1 × 10−3 m, which corresponds to severe hyperhomocysteinemia. the results of experiments on culturing of cardiac tissue explants in the...

Aldosterone-induced intestinal Na(+) absorption is mediated by increased activities of apical membrane Na(+)/H(+) exchange (aNHE3) and basolateral membrane Na(+)-K(+)-ATPase (BLM-Na(+)-K(+)-ATPase) activities. Because the processes coordinating these events were not well understood, we investigated human intestinal Caco-2BBE cells where aldosterone increases within 2-4 h of aNHE3 and alpha-subu...

PURPOSE In a previous study, an increase in Na,K-ATPase alpha 2 expression was detected in the epithelium of porcine lenses exposed to amphotericin B, an ionophore that also increases lens sodium and stimulates active sodium transport. The purpose of the present study was to determine whether an increase of Na,K-ATPase alpha 2 synthesis is a response to an episode of rapid Na-K transport or whe...

Vascular smooth muscle cell hypertrophy is a normal compensatory state that may play a pathogenic role in hypertension. Angiotensin II stimulates a hypertrophic response in cultured vascular smooth muscle cells. As part of the growth response, angiotensin II rapidly activates the Na(+)-H+ exchanger, increasing Na+ influx. Because Na+, K(+)-ATPase is the major cellular mechanism for regulating i...

Na,K-ATPase α4 is a testis-specific plasma membrane Na+ and K+ transporter expressed in sperm flagellum. Deletion of Na,K-ATPase α4 in male mice results in complete infertility, making it an attractive target for male contraception. Na,K-ATPase α4 is characterized by a high affinity for the cardiac glycoside ouabain. With the goal of discovering selective inhibitors of the Na,K-ATPase α4 and of...

In relation to dietary Na(+) intake and aldosterone levels, collecting duct principal cells are exposed to large variations in Na(+) transport. In these cells, Na(+) crosses the apical membrane via epithelial Na(+) channels (ENaC) and is extruded into the interstitium by Na,K-ATPase. The activity of ENaC and Na,K-ATPase must be highly coordinated to accommodate variations in Na(+) transport and...

The Na+-K+-ATPase, localized in the basolateral membrane of enterocytes plays a major role in nutrient transport in the small intestine by transferring K+ ions into and Na+ out of the cell. Within the enterocyte, homeostasis is maintained by active exclusion of Na from the cell by the Na+,K+-adenosine triphosphatase (ATPase) or sodium pump. Because much of the intestinal nutrient transport is b...

The effect of Annona squamosa, Lawsonia inermis and their combination with other herbal molluscicides were studied on different enzyme activity in the nervous tissue of Lymnaea acuminata. Twenty-Four hour in vivo exposure to 40% and 80% of 24 h LC50 of plant derived molluscicides and their combination with other molluscicides such as Cedrus deodara, Azadirachta indica oil, Allium sativum, Polia...

We set out to determine whether cellular hypoxia, via mitochondrial reactive oxygen species, promotes Na,K-ATPase degradation via the ubiquitin-conjugating system. Cells exposed to 1.5% O2 had a decrease in Na,K-ATPase activity and oxygen consumption. The total cell pool of alpha1 Na,K-ATPase protein decreased on exposure to 1.5% O2 for 30 hours, whereas the plasma membrane Na,K-ATPase was 50% ...