608 BIOTIN 



preferential accelerated rate of reduction over that of total cholesterol, it 

 may be assumed that^^ biotin plays a role mainly in the esterification and 

 perhaps even in the formation and storage of fatty acids, and only inci- 

 dentally in the storage of cholesterol. 



The inability to store cholesterol or cholesterol esters in the liver in 

 biotin deficiency may thus be contrasted with the "biotin fatty liver." 

 Some discrepancies in findings reciuire further studies. 



J. BIOTIN AND SEX HOEMONES 



All manifestations of biotin deficiency develop earlier and at a lesser 

 degree of biotin undersaturation in male than in female rats.^' ■*• ^' ^^' ^^' ^^ 

 These differences are obscured in excessively severe depletion of biotin. ^^ 

 Gonadectomy produced only slight changes in deficiency symptoms in 

 males. In females it resulted in increased food intake and marked accentua- 

 tion in severity of symptoms. Removal of the gonads, however, did not 

 entirely eliminate the differences between males and females (adrenals?). 

 Implantation of diethylstilbestrol attenuated, and that of testosterone 

 pellets hastened, the development and increased the severity of biotin defi- 

 ciency symptoms. ^^ 



Hertz and Sebrell demonstrated the presence of avidin in the secretion 

 from the mucosal lining of the o\'iduct in hen and frog. It has been fiu'ther 

 shown that avidin is present only in the albumen-secreting portion of the 

 oviduct, and its production depends upon ovarian function. No a\'idin was 

 found in the oviduct of the non-laying hen.''- Mucosal scrapings from the 

 oviducts of pig, cow, and guinea pig contained no avidin.''^ The secretion 

 of avidin may be induced in the oviduct of the non-laying hen by combined 

 treatment with stilbestrol and either progesterone, desoxycorticosterone 

 acetate, or testosterone propionate.^''' ^'^ 



The fat-soluble biotin-like fraction of the plasma (FSF) (see pp. oGo, 5()G) 

 is increased in the actively laying hen.''- Total biotin activity, composed of 

 that of true biotin and of the fat-soluble fraction, is elevated fivefold in 

 the blood of the estrogen-treated sexually immature chick. In these chicks 

 the weight of the oviduct is considerably increased but the secretion 

 of avidin is not stimulated. Combined administration of stilbestrol and 



66 P. Gyorgy, J. Biol. Clum. 131, 733 (19.39). 



67 F. Stenquist, Deidsch. Med. Wochschr. 54, 1920 (1928). 



68 R. M. Fraps, R. Hertz, and W. TI. Sehroll, Proc. Soc. E.rptl. Biol. Mnl. 52, 

 140 (1943). 



69 R. Hertz, Physiol. Rev., 26, 479 (1946). 



'OR. Hertz, R. M. Fraps, and W. H. Sel)r(>ll, l'r,>r. Soc. E.rpil. Biol. Mnl. 52, 142 



(1943). 

 7' H. Hertz, H. M. Fraps, and W. II. Sebrell, ScictHr 100, 3.") (1944). 

 " W. Trager, J. Biol. Chem. 176, 133 (1948). 



