Abstract
Frei reported 1 that he was able to sensitize the skin of guinea pigs to neoarsphenamine. One of us (S) observed 2 a high degree of variation in the response of different series of guinea pigs to this type of sensitization. Mayer and Sulzberger 3 concluded that the composition of the diet was of fundamental significance, for, the animals receiving summer fodder were resistant to sensitization (only 0 to 12% becoming sensitized), whereas animals receiving winter fodder were sensitizable 75 to 100%. The “seasonal” difference in the diets depended upon the inclusion or omission of greens. Sensitization of guinea pigs to paraphenylene diamine as well as their reaction to infection with a virulent strain of tubercle bacilli have been reported to be similarly influenced by diet. 3 , 4
Our attention was directed to the vitamin C content of the rations. When pure crystalline vitamin C became available, it was decided to use the synthetic product∗ as the source of vitamin C instead of citrus or tomato juice.
Young guinea pigs weighing approximately 250 gm. were placed upon the scorbutogenic diet described by Demole, 5 consisting of 2 kilos oat flakes and one kilo dried whole milk (previously heated for 2 hours at 120°C.) made into cakes with the aid of 6 egg whites and baked on a greased pan for 20–25 minutes. 200 mg. per week of cod liver oil were fed each guinea pig and a small amount of dried hay supplied. After 10 to 15 days on this diet, the negative control animals commenced to lose weight and showed early signs of scurvy. Three to 4 weeks later they died and at autopsy further manifestatations of scurvy were found.
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