[Comparative study of the antiarrhythmic activity of L-, D-and DL-stereoisomers of potassium magnesium aspartate].

Injection forms of potassium (K) and magnesium (Mg) aspartate (Asp) were compared in preventing cardiac disorders caused by electrolytic disturbances, primarily low K and Mg levels (e.g. caused by the treatment with cardiac glycosides and diuretic drugs). Widely used K- and Mg-Asp preparations (asparkam, panangin, pamaton) are synthesized from aspartic acid representing a racemic mixture of L- and D-stereoisomers. Differences in metabolism and utilization of D- and L-amino acids probably influence the pharmacological properties of K and Mg L- and D-aspartates. Moreover, the pharmacologically effective doses of Mg and K salts can induce toxicity, which depends on the nature of anions. The aim of this study was to compare of antiarrhythmic action of K and Mg L-, D-, and DL-Asp stereoisomers using calcium chloride (CaCl2) and aconitine induced arrhythmia models in rats and strophanthin-K induced arrhythmia model in guinea pigs. It was found that intravenously administered K- and Mg-L-Asp exhibited higher activity compared to K- and Mg-D- and DL-Asp on the strophanthin-K, CaCl2, and aconitine induced arrhythmia models. Indeed, K- and Mg-L-Asp more effectively decreased the incidence of arrhythmias, increased the time to onset of the first arrhythmia, decreased percentage loss of rats, and increased the survival life of animals after the first arrhythmia onset in rats with arrhythmias induced by strophanthin-K and CaCl2 as compared to K and Mg-D- and DL-Asp. At the same time K- and Mg-L-Asp was better than D- and DL-Asp with respect to acute toxicity (LD50), effective dose (ED50) and antiarrhythmic (therapeutic) ratio (LD50/ED50) in rats with aconitine-induced arrhythmia model.

Comparative study of the efficacy of potassium magnesium L-, D- and DL-aspartate stereoisomers in overcoming digoxin- and furosemide-induced potassium and magnesium depletions.

Potassium and magnesium aspartate (K,Mg aspartate) is used in treating and preventing cardiac disruptions caused by electrolytic disturbances, primarily low potassium (K) and magnesium (Mg) levels (e.g. in the treatment with cardiac glycosides and diuretic drugs). Widely used, K,Mg aspartate is synthesized from aspartic acid representing a racemic mix of L- and D-stereoisomers. Differences in metabolism and utilisation of D- and L-amino acids probably have an effect on the pharmacological properties of K,Mg L- and D-aspartates, and what is more, pharmacological doses of magnesium and potassium salts may induce toxicity, which differs according to the nature of the anions. Therefore, the purpose of the present work was to study the effect of intravenously administered K,Mg L-aspartate in comparison with its D- and DL-stereoisomers on K and Mg restoration rates in plasma, erythrocytes and myocardium and to evaluate the urine excretion rate of amine nitrogen and Mg in digoxin and furosemide treated rats. To induce Mg depletion, male rats, weighing 180-200 g, were given furosemide and digoxin at doses of 30 mg/kg (i.p.) and 0.25 mg/kg (i.p.) daily for 14 days. After 14 days K,Mg L-, D- and DL-aspartates were administered with simultaneous furosemide and digoxin treating at dose of 100 mg/kg (i.v.), which corresponds to 46.95 mg of Mg aspartate (i.e. Mg = 3.96 mg) and 53.05 mg of K aspartate (i.e. K = 12.12 mg) per kg bodyweight. Erythrocyte, plasma and urine Mg levels were measured by colorimetric assay using the method based on the staining reaction of Mg and thiazole yellow. Myocardium Mg and K content and erythrocyte K levels were determined by flame atomic absorption spectroscopy. The level of amine nitrogen was measured by colorimetric assay using the method based on the staining reaction with ninhydrin. It was shown that K,Mg L-aspartate administration leads to higher compensation of K and Mg deficiency in rats with furosemide and digoxin induced K and Mg depletion, as compared with D- and DL-stereoisomers. According to the K and Mg deficiency correction rate, K,Mg aspartates may be ranged in the following order: K, Mg L-aspartate > K,Mg DL-aspartate > K,Mg D-aspartate. It was shown that after administration of K,Mg L-aspartate, daily urine excretion of amine nitrogen and Mg is less than after D- and DL-stereoisomer administration. According to the quantity of excreted amine nitrogen and Mg in urine, K,Mg aspartates may be ranged in the following order: K,Mg D-aspartate = K, Mg DL-aspartate > K,Mg L-aspartate. So, K,Mg L-aspartate is more beneficial in the treatment of several forms of primary Mg and K deficiency than K,Mg DL-aspartate and K, Mg D-aspartate.