[The influence of bilirubin on the mechanogram of isolated, spontaneously beating frog heart].

It was shown that bilirubin in its unconjugated form does not only harm the central nervous system. Clinical observations indicate that the toxic effect under certain conditions affects also the heart. In a simple experimental model the influence of free bilirubin on the activity of the heart was investigated. In 69 adult frogs the heart was isolated and exposed sequentially to solutions of different bilirubin concentrations while the heart actions were registered. There was no significant change in the activity of the heart under the influence of bilirubin although concentrations were reached which according to the results of other authors harm cell cultures or evoke in the newborn disturbances in various organs. As a possible explanation, the nonsusceptibility of the heart muscle to bilirubin, the short duration of exposure, and the different behavior of newborn and adult organs is discussed.