BACKGROUND The Na+,K+-adenosine triphosphatase is a ubiquitous enzyme system that maintains the ion gradient across the plasma membrane of a variety of cell types, including cells in the central nervous system. We investigated the antinociceptive effect of intrathecally administered ouabain and examined its potential interaction with spinal morphine and lidocaine. METHODS Using rats chronical...

Ouabain (OUA) is a cardiotonic steroid with an immunomodulatory and anti-inflammatory role in different experimental models. Currently, the potential antineoplastic effect of OUA has been studied, however, research needed to better understand during tumor development. Therefore, our aim was investigate effects on Ehrlich (ET) development vitro vivo. To evaluate cytotoxic ET cells were incubated...

Although known as a Na,K-ATPase inhibitor, several other cellular and systemic actions have been ascribed to the steroid Ouabain (Oua). Particularly in the immune system, our group showed that Ouabain acts on decreasing lymphocyte proliferation, synergizing with glucocorticoids in spontaneous thymocyte apoptosis, and also lessening CD14 expression and blocking CD16 upregulation on human monocyt...

The long-term effects of ouabain on transepithelial Na(+) transport involve transcriptional downregulation of apical Na(+)/H(+) exchanger isoform 3 (NHE3). The aim of this study was to determine whether ouabain could acutely regulate NHE3 via a posttranscriptional mechanism in LLC-PK1 cells. We observed that the basolateral, but not apical, application of ouabain for 1 h significantly reduced t...

Sodium-dependent transporters are inhibited indirectly by the Na-K-ATPase inhibitor ouabain. Here we report stimulation of sodium-hydrogen exchange (NHE) in ouabain-treated cells. BCECF was used to measure cytoplasmic pH in cultured rat optic nerve astrocytes. Ammonium chloride was applied to acid load the cells. On removal of ammonium chloride, cytoplasmic pH fell abruptly, then gradually reco...

Ouabain has recently been identified as an endogenous Na(+)-K+ pump inhibitor. We administered ouabain chronically to normotensive rats with varying degrees of reduced renal mass (RRM) and to normal two-kidney rats to see whether hypertension could be produced. Normal male Wistar rats and rats with 25%, 60%, and 70% RRM received ouabain (13.9 micrograms/kg per day IP) in normal saline for 4 wee...

Ouabain is a common tool to explore the pathophysiological changes in adult mammalian cochlea in vivo. In prior studies, locally administering ouabain via round window membrane demonstrated that the ototoxic effects of ouabain in vivo varied among mammalian species. Little is known about the ototoxic effects in vitro. Thus, we prepared cochlear organotypic cultures from postnatal day-3 rats and...

Ouabain increases vascular resistance and may induce hypertension by inhibiting the Na+ pump. The effects of 0.18 and 18 microg/kg, and 1.8 mg/kg ouabain pretreatment on the phenylephrine (PHE; 0.1, 0.25 and 0.5 microg, in bolus)-evoked pressor responses were investigated using anesthetized normotensive (control and uninephrectomized) and hypertensive (1K1C and DOCA-salt treated) rats. Treatmen...

Binding of ouabain to Na(+)/K(+)-ATPase activates tyrosine phosphorylation of the epidermal growth factor receptor (EGFR), Src, and p42/44 mitogen-activated protein kinases (MAPKs) in both cardiac myocytes and A7r5 cells. Here, we explored the roles of Src and the EGFR in the ouabain-invoked pathways that lead to the activation of MAPKs. Exposure of A7r5 and LLC-PK1 cells to ouabain caused a do...

We showed recently that mitochondrial ATP-dependent K(+) channel (mitoK(ATP)) opening is required for the inotropic response to ouabain. Because mitoK(ATP) opening is also required for most forms of cardioprotection, we investigated whether exposure to ouabain was cardioprotective. We also began to map the signaling pathways linking ouabain binding to Na(+)-K(+)-ATPase with the opening of mitoK...