Histological study of the effects of hycanthone on the frog's ventricle in the presence of a soluble sodium salt of prednisolone hemisuccinate.

The histological picture of the ventricle of frog's heart exposed to the action of Hycanthone in Ringer's solution in concentration of 1:1 was compared with that of the ventricle of frog's heart exposed to Ringer's solution devoid of the drug and with that of frog's heart exposed to Ringer's solution containing Hycanthone in concentration of 1:1 in addition to a soluble sodium salt of prednisolone hemisuccinate in concentration 1:1. It was found that the structure of the ventricle of the heart exposed to the action of Hycanthone in the presence of the soluble sodium salt of prednisolone hemisuccinate was close in pattern to the structure of the ventricle of the heart exposed to Ringer's solution alone, while the ventricle of the heart exposed to Hycanthone alone in Ringer's solution in concentration of 1:1 was different in that the muscle fibres swollen, the cytoplasm was paler with less marked striations, the nuclei were swollen and paler, the epicardial cells were swollen and the connective tissue pattern was distorted. This denoted that the morphological changes that occurred in response to Hycanthone in the presence of the soluble sodium salt of prednisolone hemisuccinate was less marked than those which occurred in its absence.

The effects of dyphylline [7-(2,3-dihydroxypropyl) theophylline] on the toxicity of hycanthone on the frog's heart.

The effects of the topical application of Dyphylline in concentrations of 1.0 mg/1.0 ml and 10 mg/1.0 ml Ringer's solution and 25 mg/1.0 ml, 0.065% NaCl solution (the content of ampoules in clinical use) were investigated on frog's heart in situ. Dyphylline in all of the above concentrations had a stimulatory effect on the frog's heart. Hycanthone methanesulphonate in concentration of 1.0 ml/1.0 ml when topically applied to the frog's heart had a depressant effect on both of the contractility and rhythmicity. The depressant effects of Hycanthone in concentration of 1:1 were compared before and after the topical application of Dyphylline in the above mentioned concentrations. It was found that Dyphylline in concentration of 1.0 mg/1.0 ml could partially antagonize the depressant effect of Hycanthone on the heart rate but not on the force of contraction. Dyphylline in concentration of 10 mg/1.0 ml could partially antagonize the depressant effects of Hycanthone on both of the heart rate and the force of contraction. Dyphylline in concentration of 25 mg/1.0 ml could completely antagonize the depressant effects of hycanthone on both of the heart rate and the force of contraction.