Venous Potassium Research Articles

Relation of potassium and glucose release from the liver in the unanesthetized dog.

SummaryThe time course of hepatic metabolic and hemodynamic events after hormone-induced glycogenolysis is described in the un-anesthetized dog. Increased concentration of hepatic venous plasma potassium and rate of hepatic potassium output occurred after intravenous administration of glucagon, .02 mg/kg. These effects were noted within 20 to 30 seconds after injection and became maximal within 2 minutes. Increased rates of hepatic blood flow and hepatic glucose output occurred 10 to 20 minutes after glucagon administration. A similar but more rapid pattern was observed after intravenous administration of epinephrine, 1 μg/kg. Maximum hepatic venous plasma potassium and hepatic potassium output was reached at about 1 minute after injection. Increased hepatic blood flow occurred during or shortly after increased hepatic venous potassium concentration. Increased rate of hepatic glucose output did not begin until after the potassium efflux from the liver. Hepatic glucose output reached a maximum 3 to 6 minut...

The Effects of Acute Induced Hypoxia on Coronary Circulation. Hypoxia and Cardiac Oxygen Metabolism

Coronary sinus catheterization was performed on men with normal heart and those with coronary sclerosis, and on dogs with normal heart and those with coronary vascular lesions. Effects of hypoxia upon cardiac oxygen metabolism, especially on regulation of the coronary blood flow were studied. Results were as follows : 1) with regard to the rate of increase in coronary blood flow due to hypoxia, there was no statistical significance of differences between the group of normal men and that of coronary sclerosis. In dogs, however, the rate of increase was lower in dogs with coronary vascular lesions than in the normal dogs.2) In men, there was inverse correlation between the rate of decrease in arterial oxygen saturation and the rate of increase in coronary blood flow due to hypoxia.3) As for the rate of decrease in coronary sinus oxygen tension due to hypoxia, there was no statistical significance of differences between the two groups of men. In dogs, the rate of decrease was less in the group of coronary lesions than in the normal. The rate of decrease in arthrio-coronary venous difference due to hypoxia was less in the dogs with coronary lesions than in normal dogs, though in men there was no statistical significance between the two groups.4) In resting state there seemed to be an inverse correlation between the coronary blood flow and the arterio-coronary venous oxygen difference. The correlation became more apparent when hypoxic state was induced. In the coronary groups of both men and dogs, the increase in coronary blood flow was not so much as it should be expected from the decrease in the arterio-coronary venous oxygen difference.5) In men, there was good inverse correlation between coronary sinus oxygen tension and myocardial oxygen extraction coefficient in hypoxic state, as well as in resting state.6) In hypoxic state in men, release of potassium from myocardium was noted in 6 of 9 cases with coronary sclerosis. In 5 of these 6, there was an increase in myocardial oxygen extraction coefficient.On the contrary, myocardial oxygen extraction coefficient was decreased or not changed in those in which there was measurable myocardial uptake of potassium or no arterio-coronary venous potassium difference.

Potassium movement in patients with familial periodic paralysis: Relationship to the defect in muscle function

Study in two patients with familial periodic paralysis and in one with non-familial periodic paralysis of potassium movement and associated changes in muscle function yielded the following results: 1. 1. The administration of glucose produced a greater fall in venous potassium concentration in these patients than in normal subjects, probably owing to greater uptake of the ion by muscle. 2. 2. The administration of epinephrine may have produced greater uptake of potassium by muscle in these patients than in normal subjects, but the difference was less marked than in the case of glucose. 3. 3. The administration of insulin resulted in evidence of movement of potassium into muscle, in contrast to movement out of muscle in normal subjects. 4. 4. Attacks of weakness which occurred spontaneously or following the administration of food, glucose or insulin were associated with reduced plasma potassium concentration and abnormally high arteriovenous difference, indicating abnormal uptake of the ion by muscle, and with reduction in muscle responsiveness to nerve stimulation and acetylcholine, in propagation of excitation, and in contractility. 5. 5. In these patients muscle contraction during attacks, even though very weak, caused more loss of potassium from muscle and greater increase in muscle responsiveness and contractility than prior to the attack, or than in normal subjects. 6. 6. Spontaneous recovery from weakness was associated with leakage of potassium from muscle, and was accelerated by exercise. During recovery following the administration of potassium chloride there was, first, slight improvement in strength which was followed by loss of potassium from muscle, and then more rapid improvement. 7. 7. The weakness of periodic paralysis appears to be due to the following sequence: (1) abnormal uptake of potassium by muscle; (2) marked increase in the intracellular to extracellular concentration ratio of this ion; (3) hyperpolarization of the muscle membrane; and (4) reduction in muscle responsiveness to nerve stimulation, in propagation of excitation, and in contractility.

Acute elevation of hepatic venous and arterial serum potassium during hyperventilation

Acute elevation of hepatic venous and arterial serum potassium during hyperventilation