IX. METAHOLISM 43 



pyridoxim\ paiitotluMiic acid, and clioliiic. 'llw addition of PABA or folic 

 acid alono to tlio basal puiilicd latioii did, ho\v(>vcr, stimulate hemoglobin 

 formation to a small extent. 



Johnson and James'"^ could lind no definite evidence for a requirement 

 for PAl^A or inositol when their combined deficiencies were superimposed 

 on a choline deticienc}^ although their omission from the diet of growing 

 pigs appeared to accentuate the degree of fatty infiltration of the liAcr. 



6. Fish 



McLaren c( a/.'°^ found that a deficiency of PABA in the diet of trout 

 results in fatty livers, so that PABA is considered to be a vitamin for this 

 species. The requirement of trout for PABA is placed at 10 to 20 mg. per 

 100 ff. of ration. 



IX. Metabolism 



LEMUEL D. WRIGHT uiid PETER A. TAVORMINA 



A. EXCRETION IN LOWER ANIMALS 



The fate of intraperitoneally administered N'Mabeled PABA has been 

 studied in the mouse by Lustig et al} A male mouse weighing 22 g. received 

 three subcutaneous doses of 10 mg. within a 24-hour period. Nineteen hours 

 after the last injection, however, only traces were found in the organs, but 

 227 7 of N^^, corresponding to 82% of that injected, was present in the 

 excreta. 



Similar results with respect to the rapidity with which administered 

 PxABA is excreted by mice were reported by Tabor et al? One gram of PABA 

 per kilogram as the sodium salt was administered either orally or intra- 

 peritoneally to mice. At intervals after administration of the PABA, ani- 

 mals were homogenized in a Waring Blendor with water. Aliquots of each 

 homogenate were assayed for total amine (Bratton-Marshall method, 

 hydrolysis in 6 N HCl at 100° for 30 minutes). In mice killed immediately 

 after administration of the drug, all the PABA is recovered in the tissues. 

 /Vfter oral or intraperitoneal administration the total amine disappears 

 rapidly, so that only 50% is present in the tissues after 3 houi's, and little, 

 or none at all, after 8 hours. 



">« B. C. JohiLson iiud M. F. .J.imcs, ./. Nutrition 36, 339 (1948). 

 '"9 B. A. McLaren, E. Keller, 1). .J. O'Doiiiiell, mihI C. A. Klvelijem, Arch. Biochcui. 

 15, 169 (1947). 

 ' B. Lustig, A. R. Goldlail), and G. Gerstl, Arch. Biochem. 5, 59 (1944). 

 "- C. W. Tabor, ^L V. Freeman, J. Baily, and P. K. Smith, ./. Pharmacol. Exptl. 

 Therap., 102, 98 (1951). 



