690 PANTOTHENIC ACID 



levels. They found that at ordinary normal plasma concentrations (0.10 to 

 0.32 7 per milliliter) only a trace of pantothenic acid was excreted in the 

 urine and that the renal clearance was of the order of 0.2 to 0.5 milliliter 

 per minute. On increasing the plasma concentration by oral or intravenous 

 administration to about 0.5 y per milliliter, there was an abrupt rise in the 

 calculated clearance. When the plasma concentration was increased to 1.2 

 7 per milliliter, the renal clearance approximated the glomerular filtration 

 rate and the further increase of the plasma concentration to or above 100 

 7 per milliliter did not alter materially the clearance ratio. These experi- 

 ments were done with dogs. 



Pelczar and Porter^^ determined the plasma concentration of pantothenic 

 acid in seventeen normal subjects and found that it ranged from 0.030 to 

 0.099 7 per milliliter of blood and averaged 0.059 7 per milliliter. These 

 levels are lower than those observed in 1946 by Wright et al. at the time 

 they did renal clearances. ^^ Pearson ^^ reported the blood levels as varying 

 from 0.020 to 0.28 7 per milliliter. The discrepancy is probably due to the 

 organism that was used in the microbiological assays. Wright et al. used 

 Lactobacillus arabinosus. Pearson used Lactobacillus casei e, and Pelczar 

 and Porter used Proteus morganii. 



Spies et alJ^ made the interesting observation that the pantothenic acid 

 content of the blood was decreased in patients with pellagra, beriberi, and 

 riboflavin deficiency. They found that the administration of 20 mg. of 

 pantothenate daily increased the blood pantothenic acid and riboflavin 

 levels. Siegel et al^^ studied blood pantothenic acid in patients with multiple 

 sclerosis and did not observe any significant differences from the blood 

 levels in normal subjects. 



Another group of workers studied the pantothenic acid content of can- 

 cerous tissue and analj^zed malignancies of liver, myocardium, brain, lung, 

 spleen, kidney, and muscle.'^- The pantothenic acid content in micrograms 

 per gram of fresh tissue was highest in carcinoma of the liver and lowest 

 in carcinoma of the lung and spleen. The pantothenic acid content of liver 

 was 31 7 per gram, of kidney 16 7 per gram, and of lung and spleen 5 7 

 per gram. The figures were lower than determined in rat liver carcinoma. 



In Oldham's study, the dietary intake of pantothenic acid was lower 

 (2 to 5 mg.) than what would normally be consumed in an ordinary diet 

 (7 mg.). It seems obvious that the subjects in this study had adequate 

 supplies of pantothenic acid in their tissues because the excretion paralleled 



'0 T. D. Spies, S. R. Stanbery, R. J. Williams, T. H. Jukes, and S. H. Babcock, /. 



Avi. Med. Assoc. 115, 523 (1940). 

 " L. Siegel, T. J. Putnam, and J. G. Lynn, Proc. Soc. Exptl. Biol. Med. 47, 362 (1941). 

 " A. Taylor, M. A. Pollack, M. J. Hofer, and R. J. Williams, Cancer Research 2, 752 



(1942). 



