The influence of potassium ions on the cardiac musculature seems according to experiments available up to the present to correspond to that on skeletal muscles. If a frog heart, brought to a standstill through a Stannius ligature, is treated locally with KCl, then exactly as in a frog sartorius there appears a rest stream which again diminishes by washing off the KCl with Ringer’s solution.
HEART
The reduction of irritability or paralysis of the heart muscle through potassium has been confirmed by experiments on living frogs and rabbits. In order to obtain this necessarily slight increase of potassium-ion content of tissue fluid, in consequence to the rapid equalization capacity of the kidneys and transference to nonsensitive tissue cells, the potassium salt must be injected subcutaneously or intravenously. If the K2O content in the blood increased from the normal 0.025- 0.03 per cent to 0.07- 0.08 per cent, then diastolic cardiac standstill occurs. On subcutaneous injection in frogs the pulse frequency sinks and again increases after some time. The blood becomes strongly carbonic-acid containing; the heart is darkly colored. That the cardiac action is conditioned primarily and not through a defect in oxygen can be proven through a study conducted in an oxygen atmosphere. The action occurs on the heart muscle alone, because it also occurs in the ganglion-free heart muscle. In rabbits one also observes sinking of the pulse frequency and single momentary sudden standstill of the pulse curve.
Potassium added alone to sodium chloride as nutrient fluid of the heart prolongs the heart beat, reduces the tonus and leads finally to diastolic cardiac standstill. Potassium is here the outspoken antagonist to calcium.
Kolm and Pick have shown that the potassium content of the blood and heart wall is one of the most important pre-conditions for the self-regulation of the heart. It proves that the influence of potassium on the various sections of the heart is different. One can recognize to some extent the physiologic function of potassium on the heart of cold-blooded animals.
They found:
(1) KCl stimulates stimulus production in the upper heart, which expresses itself in an increase of inotropy, at times also in chronotropy.
(2) CaCl2 causes diastolic standstill in the heart washed free from potassium; the appearance of calcium contracture is bound to the presence of potassium in the heart.
(3) KCl depresses the tertiary centers of the automatically beating heart even in doses which are non-toxic for the heart as an entirety and which even stimulate the sinus and auricular activity; it is able to remove the excitation of the automatic ventricular centers set into stimulation by calcium and barium chloride.
(4) The capacity of potassium to release contracture of a heart which has been induced by calcium depends upon an increase of impulse which goes from the upper heart (sinus and auricle) to the ventricle found in preparation for contracture from calcium.
(5) On the automatically beating ventricle, potassium chloride is not able to conduct into contracture a heart which has been prepared for contracture by calcium chloride; much more a contracture induced by calcium or barium chloride in the automatic beating ventricle will be released through the addition of KCl.
(6) Potassium salts are able to prevent fibrillation through increase in the nomotopic stimulus and depression of the tertiary ventricular centers.
The toxic actions of potassium are not observed in a resorption from the gastro-intestinal canal because a definite increase of the amount of potassium ions in the blood plasma is not able to take place in consequence to the equalization processes of the organism. But if symptoms have been observed from small doses of potassium salts which point toward an affinity to skeletal and cardiac muscle which was discovered experimentally much later, then it must be considered that the type and form of the preparation administered and furthermore a special potassium sensitivity must have been responsible for the symptoms. In order to disturb the potassium economy it does not necessarily follow that the point of departure must be taken from an increase of concentration in the fluid perfusing the tissues, but it is possible that from especially fine subdivision the route may be entirely over the vegetative nervous system, that a catalytic -like disturbance of the potassium-ion potential occurs, particularly when there is already a labile equilibrium in this direction. The excitation of an accelerated potassium- ion wandering can act disturbing in the one case, regulating in another. In any case, observations free from objections made in homoeopathic provings with potassium salts cannot be denied because the possibility of explanation available for the effects known from animal experimentation cannot be utilized at present. For the explanation of the mechanism of ion effects directly up- on the receptive cells, pharmacologic animal experiment can, however, offer a certain basis.
The influence of alkali salts on smooth muscle is of another type than upon striated muscle. Here the plasma-membrane resistance does not seem to exist with an elective permeability. Consequently, the potassium ion acts more strongly de-swelling, shortening and tonus increasing than does the sodium ion.
VAGUS
The influence of an increase of potassium from with out on the skeletal muscle and cardiac musculature is equally tonus reducing, on the contrary in smooth muscle tonus increasing. If, now, one accepts the finding of Dufurdi that the irritability of the vagus is increased through potassium salts, so it seems that this action can be connected with the action of potassium on the receptive organs as a vagus effect.
Zondek found that enrichment of potassium in the nutrient fluid which is nourishing a frog heart acts as a vagus stimulus (calcium enrichment acts like a sympathetic stimulus). On the other side, vagus stimulation leads to intracellular potassium shifting (sympathetic stimulation leads to alterations of the calcium content of a cell). Between parasympathetics and potassium apparently exists a reciprocal relation such as we know exists between nerves and hormones. This relationship is represented best in the study of Loewi. Accordingly materials form in the isolated heart after stimulation of the parasympathetic nerves which again influence another heart in the same way. IF a cold-blooded heart filled with Ringer’s solution is faradically stimulated through the vagus, then the fluid which is obtained from the heart is able to bring about a vagus effect in a normally beating heart. According to Loewi the product formed through vagus stimulation naturally cannot be potassium because in his studies the action was removed by atropine which is not the case in increased potassium effect. At present we can only interpret the finding in that by a stimulation through a nerve to a muscle cell, the ion shifting thereby provoked is again able to evoke the same action as the nerve stimulation. This activation of a mixture of ions through the vital process of nerve muscle excitation in this same direction best enlightens us on the fineness of such reciprocal actions upon one another and makes the action of drugs in high dilution understandable when sensitivity exists, whether in a proving on the healthy, or in a potassium patient. Would not the suitable potassium preparation succeed in stimulating through the medium of the vagal connections, and intervene in a vicious circle?
If one recalls that voluntary muscle also has a vegetative innervation on which its tonus is dependent, then one can consider how it is possible to regulate the potassium balance between the inside and outside of the muscle fibrils by the vegetative nerves, and thereby the tonus through potassium as a remedial agent.
Placing potassium and the vagus parallel need not be overstretched as has occurred in the counterbalancing of the relations of K:Ca as the vagus: sympathetic by S. G. Zondek. Indeed, in general, a potassium preponderance corresponds to increased vagus influence and it is also very probable that the tonic action of potassium intermediates and regulates via the vagus. But, for example, the influence of potassium and calcium ions in the regulation of the heart does not agree throughout with the functions of the vagus and sympathetic. While the vagus depresses all parts of the heart from the sinus node to the ventricle, potassium stimulates the upper part of the heart.
WATER ECONOMY
The diuretic action of large amounts of salt in the healthy, which is opposite to the effect in patients with damaged capillaries, need not be considered in detail here. There it is merely concerned with an osmotic equalization which has nothing to do with special affinities of the single ions. Of most significance is that potassium acetate is especially useful as a diuretic because potassium carbonate which arises out of it in the organism diffuses less than, for example, sodium chloride.
Leeser, a Consultant Physician at the Stuttgart Homeopathic Hospital and a member of the German Central Society of Homeopathic Physicians, fled Germany in 1933 after being expelled by the German Medical Association. In England Otto Leeser joined the staff of the Royal London Homeopathic Hospital. He returned to Germany in the 1950s to run the Robert Bosch Homeopathic Hospital in Stuttgart, but died shortly after.
Otto Leeser wrote Textbook of Homeopathic Materia Medica, Leesers Lehrbuch der Homöopathie, Actionsand Medicinal use of Snake Venoms, Solanaceae, The Contribution of Homeopathy to the Development of Medicine, Homeopathy and chemotherapy, and many articles submitted to The British Homeopathic Journal,