PANTOTHENIC ACID 



80^ and 50 to 100 /xg. per day.® According to K. Unna and G. V. 

 Richards ^ the daily maintenance requirement for the rat falls from 

 100 /xg. at three weeks of age to 25 /xg. at ten weeks, but it is not 

 related to weight or food consumption. K. Schwartz ^^ stated that, 

 after an induction period, each /xg. of additional pantothenic acid 

 produced a 62-5-mg. increase in the weight of young rats up to 20 g. 

 but that to increase the weight further the presence of another factor, 

 known as " factor 125 " (see page 608), was necessary. The nature of 

 this additional factor seems never to have been elucidated. The 

 amount of pantothenic acid required to maintain the health of rats 

 was not increased by a rise in temperature, being the same at 91° F. 

 as at 68° F., namely, 6 mg. per kg. of bodyweight.^^ 



The requirements for mice appear only to have been given in terms 

 of the dietary intake ; they are stated to be 2 mg. per 100 g. of diet.^^ 



Puppies are said ^^ to require 100 /xg. of calcium pantothenate per 

 kg. of bodyweight per day — considerably less, weight for weight, than 

 the amount accepted as being necessary for the rat. Shetland ponies 

 required proportionately less, namely 38 /xg. per kg. per day.^^° 



Black Minorca chicks on a pantothenic acid-deficient diet ex- 

 hibited a partial depigmentation of the feathers (page 369), which was 

 prevented by as little as 5 /xg. per day of pantothenic acid.^* More 

 was required to maintain optimal reproduction and egg production, 

 however, namely, 1200 to 1700 and 700 /xg. per 100 g. of food respec- 

 tively. ^^ From 750 to 1000 /xg. per 100 g. of diet were required to 

 ensure that the eggs hatched and that the chickens survived and 

 showed no signs of pantothenic acid deficiency. The minimum blood 

 level consistent with satisfactory reproductive performance was 0-45 mg. 

 per ml. and the minimum amount in the egg 9-5 /xg. About 200 /xg. 

 per 100 g. of food was considered sufficient for maintenance, although 

 900 /xg. per 100 g. of diet were necessary for maximum growth. ^^ 

 Ducklings required iioo /xg. per 100 g. of diet for satisfactory growth.^' 



References to Section 12 



1. P. Gyorgy and C. E. Poling, Science, 1940, 92, 202. 



2. K. Unna and W. L. Sampson, Proc. Soc. Exp. Biol. Med., 1940, 



45, 309. 



3. K. Unna, /. Nutrition, 1940, 20, 565. 



4. K. Unna, G. V. Richards and W. L. Sampson, ihid., 1941, 22, 553. 



5. L. M. Henderson, J. M. Mclntire, H. A. Waisman and C. A. 



Elvehjem, ihid., 1942, 23, 47. 



6. G. A. Emerson and H. M. Evans, Proc. Soc. Exp. Biol. Med., 1941, 

 46. 655. 



7. K. Schwartz, Z. physiol. Chem., 1942, 275, 245. 



8. J. D. S. Bacon and G. N. Jenkins, Biochem. J., 1943, 37, 492. 



Z7^ 



