Classically described as a potent inhibitor of the sodium-potassium adenosine triphosphatase enzyme, ouabain has been further shown to act as an effective immunomodulator in mammals. Recently, our group showed that this hormone downregulates membrane CD14 (mCD14) in human monocytes, though it is not known whether monocyte activation status could modify ouabain influence. Hence, we aimed to inve...

Ouabain has shown powerful anti-proliferation activities in various cancers, but its effect on imatinibresistant chronic myeloid leukemia and toxicity normal mice not been investigated. Cell Counting Kit-8 assay was used to detect cytotoxicity reversal of ouabain with different concentration (0.01 μM, 0.1 1.0 10 μM) drug resistance imatinib-resistant cell line (K562/G01 line). Flow cytometry th...

A critical question in hypertension research is: How is long-term blood pressure controlled? Excessive NaCl ingestion or NaCl retention by the kidneys and the consequent tendency toward plasma volume expansion lead to hypertension. Nevertheless, the precise mechanisms linking salt to high blood pressure are unresolved. The discovery of endogenous ouabain, an adrenocortical hormone, provided an ...

This paper is concerned with analyzing the sidedness of action of various determinants which alter the rate of ouabain binding to human red blood cell ghosts. Thus, ouabain binding promoted by orthophosphate (Pi) and its inhibition by Na are shown to be due to inside Pi and inside Na. External K inhibits Pi-promoted ouabain binding and Nao acts to decrease the effectiveness of Ko. Similarly, in...

We showed before that Na+-K+-ATPase is also a signal transducer in neonatal rat cardiac myocytes. Binding of ouabain to the enzyme activates multiple signal pathways that regulate cell growth. The aims of this work were to extend such studies to adult cardiac myocytes and to determine whether the signal-transducing function of Na+/K+-ATPase regulates the well-known effects of ouabain on intrace...

Angiotensin II stimulates secretion of corticosteroids and an ouabain-like compound from adrenocortical cells. The angiotensin AT1 and AT2 receptor subtypes have been linked with stimulated secretion of aldosterone and endogenous ouabain, respectively, but the second messenger mechanisms involved in the latter secretion are not known. Accordingly, we investigated the effects of several pharmaco...

Na/K-ATPase can function as a signal transducer as well as an energy transducing ion pump. Cardiac glycosides (including ouabain and marinobufagin, MBG) are a new class of steroid hormones. Ouabain-activated signaling pathways lead to the induction of some early response proto-oncogenes, activation of transcription factors, and cardiac hypertrophy. Low concentration of ouabain also induced endo...

Elevated circulating levels of an endogenous ouabain (EO) have been associated with essential hypertension. To investigate structure-activity relationships relevant to blood pressure, we infused either ouabain, ouabagenin, digoxin or digitoxin at 30 ,Mg/kg/day in normal Sprague Dawley rats. After five weeks, the ouabain and ouabagenin infused rats were hypertensive, whereas blood pressures decl...

Cerebroventricular infusion of ouabain (10(-6) M) in cerebrospinal fluid produced significant increases in renal blood flow and reductions in renal vascular resistance in chloralose anesthetized, vagotomized dogs; these renal effects were not accompanied by any changes in arterial blood pressure and heart rate. Infusion of a higher concentration of ouabain (10(-5) M) enhanced significantly bloo...

Ouabain, an endogenous digitalis compound, has been detected in nanomolar concentrations in the plasma of several mammals and is associated with the development of hypertension. In addition, plasma ouabain is increased in several hypertension models, and the acute or chronic administration of ouabain increases blood pressure in rodents. These results suggest a possible association between ouaba...