Wakim, Khalil G.

Ten intact dogs were subjected to hemodialysis against a solution of low-sodium content to determine the influence of sodium depletion on myocardial binding of digoxin- 3 H. Serial determinations of serum sodium, potassium, chloride, bicarbonate, pH, and osmolality, of cardiac output, and of cardiac rhythm were obtained in these and in 10 control dogs dialyzed against the standard solution. A dose of digoxin- 3 H (0.05 mg/kg) was given intravenously after start of the dialysis and the animals were killed 1 hour afterward for measurement of myocardial radioactivity, potassium, and sodium. Significant depletion of serum sodium and chloride and myocardial sodium ( P < 0.001) occurred in all animals dialyzed against the low-sodium solution. No significant changes occurred in other serum electrolytes or pH; osmolality was maintained constant by a slow intravenous drip of 25% urea or mannitol. Myocardial radioactivity was reduced in sodium-depleted animals by 50% ( P < 0.001). The Na-K ratio was 0.40 in the myocardium of control animals and 0.26 in sodium-depleted animals. It was concluded that depletion of body sodium inhibits binding of digitalis glycosides to the myocardium during the first hour after injection of the dose.

A comparison was made of the circulatory effects of l -epinephrine and l -norepinephrine when various doses were given either intravenously or intra-arterially into anesthetized animals. No significant difference was found between the effects of identical doses of the two drugs on the arterial blood pressure, heart rate and blood flow. The intensity and duration of effect of either drug varied roughly with the dose given.

The authors investigated the effect of repeated inunction with 2 per cent glyceryl trinitrate in lanolin on the blood flow and skin temperature of the extremities in 14 cases of Raynaud's disease and in 8 cases in which Raynaud's phenomenon was associated with such vascular diseases as acrosclerosis (3 cases), chronic occlusive disease of the arteries (3 cases), occupational disease of the arteries (1 case) and livedo reticularis (1 case). The inunction almost invariably caused an increase in the blood flow and in the skin temperature of the digits in the 14 cases of Raynaud's disease.

Cerebral infarction is attended by extravasation of blood in varying degrees. The present study was undertaken to learn whether anticoagulant therapy increases the extravasation and thereby diminishes or negates possibly favorable therapeutic effects. A series of experiments on dogs is described and the clinical implications are discussed.