IX. KFFIOCTS (»K DKFICl KNCY Hi") 



■'actixation" of ijtcroyliilulainic acid is |)crloiin('il iiicdiciciil ly. 'I'his can 

 l>o corri'ctcil by (a) adininisteriiifi; excess precursor which in tills case is 

 PCJA, (b) givino; small amounts of the end product of the reac^tion, or (c) 

 correcting the scurvy. If this theory is valid, one must assume that the con- 

 \ersiou of VG\ to citrovorum factor is inc^flicient even in the presence of 

 adequate ascorbic acid, since 100 7 of i\x\ produces a submaximal hemato- 

 logical response on a diet which contains orange juice.®'* It would indeed be 

 interesting to compare the activities of PGA and CF on nutritional cyto- 

 penia in monkeys which are receixing adequate ascorbic acid. 



12. Endocrine Relationships of PGA 



A fundamental observation regarding the role of PGA in endocrine func- 

 tion was the finding by Hertz and coworkers'"®- '"^ that a deficiency of PGA 

 interfered with the response of chicks to stilbestrol. The normal oviduct 

 weight of a 100- to 150-g. chick is approximately 25 mg. Injection of 0.5 

 mg. of stilbestrol per day for 6 days to chicks on a normal stock diet in- 

 creases the size of the oviduct to approximately 1000 mg. The oviduct 

 weights of PGA-deficient chicks treated with stilbestrol were 66 to 100 mg., 

 whereas in those supplemented with 20 or 50 y of PGA and treated with 

 stilbestrol the}'- were 637 to 777 mg. It is worthy of note that the oviduct 

 weights produced by stilbestrol on the stock diet were larger (1090 to 1295 

 mg.) than those (777 mg.) which could be achieved by large amounts of 

 PGA on a purified type of diet. This indicates that there are elements in 

 the stock diet in addition to PGA which mediate the function of stilbestrol. 

 The function of PGA in the metabolism of stilbestrol is a specific one, as 

 deficiencies of pantothenic acid, riboflavin, and pyridoxine do not interfere 

 with the oviduct-stimulating action of stilbestrol on birds of comparable 

 body weight. 



Production of a PGA deficiency by the use of an antagonist "x methyl 

 PGA" also interferes with the effect of stilbestrol in stimulating growth of 

 the female reproductive tract. '"^^ '**^ The effect of the antagonist could be 

 completely reversed by PGA. A reduction in the amount of alkaline phos- 

 phatase in the ovdduct of chicks after treatment with estradiol or stilbestrol 

 has been observed in PGA deficiencies produced by "x methyl PGA.""" 



Similar results have been observed in monkeys on PGA-deficient diets. 

 Hertz'" kept sexually immature monkeys on a purified type of diet for 



'"^ R. Hertz and W. H. Sebrell, Science 100, 293 (1944). 



'<" R. Hertz, Endocrinologi/ 37, 1 (1945). 



'08 R. Hertz, Science 107, 300 (1948). 



'«» A. L. Franklin, D. Lewis, E. L. R. Stokstad, and T. H. Jukes, Poultry Science 27, 



662 (1948). 

 "" M. Andrus and M. X. Zarrow, Proc. Soc. Exptl. Biol. Med. 72, 714 (1949). 

 '" R. Hertz, Proc. Soc. Exptl. Biol. Med. 67, 113 (1948). 



