Effect of Cholesterol Exposed to Roentgen Rays on Rachitic Rats.

Hess and Weinstock 1 state that cholesterol, which has been irradiated with roentgen rays, does not cure rickets, and also that the absorption spectrum in the ultra violet of cholesterol is not changed by this kind of radiation. On the other hand, Reinhard and Buchwald 2 found that a definite change takes place in the absorption if cholesterol is irradiated in chloroform solution. This change in the absorption was similar to the change that is produced by irradiation with ultra violet. If commercial cholesterol is exposed for a short time to ultra violet radiation from a mercury arc, it obtains a curative effect on rickets and there seems to be a correlation between the activity and the change in the absorption. It seems, therefore, that cholesterol in a chloroform solution might obtain anti-rachitic properties by being exposed to roentgen radiation.

After some preliminary tests with the production of rickets in rats, the following experiment was carried out. Through the courtesy of Dr. Cornelia Kennedy a litter of 8 rats was obtained after weaning, at the age of 28 days. The mother rat had been fed on Steenbock's diet 3 which is poor in vitamine A. The eight rats were put on Steenbock and Nelson's diet No. 2966 4 free from vitamine D. Rats C and D were on this diet alone; A and B received 0.2 cc. of codliver oil per day; E and F received unirradiated cholesterol, and G and H received cholesterol which had been exposed to roentgen rays while dissolved in chloroform. The codliver oil was fed by means of a pipette. The cholesterol was administered by pouring 1 cc. of a solution of 0.6 gr. of Kahlbaum's cholesterol in 100 cc. chloroform on the day's ration and the chloroform evaporated off at room temperature. Any food remaining was added to the next ration.