Einige weitere physiologische Erfahrungen über das bestrahlte Ergosterin und seine Umwandlungsprodukte.

Abstract

As a result of apparently extensive experiments on dogs, rabbits and other animals, the authors conclude: The poisoning with irradiated ergo-sterol which has been designated by many authors as hyper-vitaminosis is not due to the administration of an excessive dose of vitamin D but is a consequence of the administration of a "calcinose factor" which is formed during the irradiation. The quantitative relationship between the concentration of vitamin D and the. "calcinose factor" appears to vary within narrow limits, whether one irradiates with Mg spark or with a mercury vapor light with or without filters or whether one alters the solvent or the time of the irradiation. Only in this way can one explain why in a rather superficial evaluation of the antirachitic and toxic minimal dose a parallelism between these two properties has been observed by numerous investigators. No one has as yet succeeded in producing a potent antirachitic but non-toxic preparation and one can, therefore, state as a 2nd finding of this work that as a result of the ultra-violet irradiation there is formed from ergosterol a chemical compound which simultaneously presents both antirachitic and Ca raising properties (the "calcinose factor"). By means of certain chemical processes such as heating and careful hydrogenation this ergosterol derivative is so changed that the antirachitic effectiveness disappears but the toxicity which is dependent upon another atomic group remains.