Background: Novel roles for the interaction of cardiotonic steroids to Na+/K+-ATPase have been established in recent years. The aim of the present study was to investigate the intracellular signaling events downstream the action of ouabain on Na+/K+-ATPase in Sertoli cell obtained from immature rats. Treatment of Sertoli cells with ouabain (1 μM) induced a rapid and transient increase in the ex...

In this study, the effect of various doses of ouabain (1, 2, and 5 mg/kg, i.p.) on weight and flow rate of submandibular gland (SMG) and changes in zinc and copper levels in pure saliva and serum of rats was investigated. The time interval between injection of drug and sampling was 30 min. In addition, the effect of a single and toxic dose of ouabain (5 mg/kg, i.p.) in various time intervals (3...

Sodium valproate (SV), an antiepileptic drug has several mechanism of action. It inhibits voltage sensitive Na+ channels and reduces intracellular Na accumulation. These actions are similar to that of both phenytoin and carbamazepine. We have investigated the direct cardiac action of SV and its effects on ouabain-induced arrhythmia in isolated guinea-pig atria. The guinea-pig atrium was dissect...

We investigated the effects of low ouabain concentrations on systolic (SAP) and diastolic (DAP) arterial pressures and on pressor reactivity in 3-month-old male spontaneously hypertensive rats (SHR). Arterial blood pressure (BP) and pressor reactivity to phenylephrine (PHE) were investigated before and after 0.18 microg/kg ouabain administration (N = 6). The influence of hexamethonium (N = 6), ...

The exogenous digitalis glycosides, ouabain and digoxin, have been widely used in humans to treat congestive heart failure and cardiac arrhythmias. Several reports have also pointed to the existence of endogenous ouabain- and digoxin-like compounds, but their precise roles in mammalian physiology and various disorders of the circulation are not clear. In an attempt to produce specific Abs for t...

From a mass culture of diploid human lymphoblasts we have isolated a subline resistant to 1 muM ouabain, and from this, a subline resistant to 10 muM ouabain. These sublines occurred spontaneously, but similar mutants were induced with 10-fold increased frequency by treatment with mutagens, in which case they could be selected as clones in soft agarose. Scatchard plot analyses of ouabain bindin...