PHYSIOLOGIC FUNCTIONS 821 



tiou of saturated acids to fat-frco diets failed to alleviate the symptoms. -"- 

 The mothers were unable to suckle their young in the absence of the required 

 nutrients; male rats were also found by Evans el al^^^ to become sterile on 

 the fat-free diets. The addition of small amounts of EFA to the fat-free 

 regimens cured the difficulties in reproduction, and even prevented their 

 development. 



More recent studies have contributed some information as to the quan- 

 titative aspects of EFA required for pregnancy and lactation. Quacken- 

 bush ct al.^*^ noted that the (juantity of EFA rec^uired for reproduc^tion in 

 rats was approximately twice that necessary to cure the dermal lesions 

 arising on a fat-free diet. Ordinary linolenic acid (9,12,15-octadecatrienoic 

 acid) was found to be relatively ineffective in permitting normal reproduc- 

 tion. There appears to be no information as to whether or not 7-linolenic 

 acid (6,9,12-octadecatrienoic acid), which Thomasson^^ reported to be as 

 active as linoleic acid in promoting growth on a fat-free diet, is effective 

 in allowing normal reproduction. Linoleic and arachidonic acids have 

 about the same biopotency insofar as reproduction is concerned. '^^ Deuel 

 and co-workers-"* reported data on pregnancy and lactation of female rats 

 which were supplemented with several levels of cottonseed oil or of methyl 

 linoleate during the period of breeding and lactation. Although fat was 

 not required by the female rat for conception, when the diet was otherwise 

 complete, the pups w-ere invariably born dead or died immediately after 

 birth. It was found that, whereas daily doses of cottonseed oil as low as 10 

 mg. insured the survival of the pups for three days, in some cases as much 

 as 200 mg. of this fat were required per day for an optimal effect. Since 

 comparable results were observed when 80 mg. of methyl linoleate were fed, 

 it was concluded that the essential fatty acids constitute the protective 

 component in fat. The requirement of the female rat for EFA during 

 pregnancy and lactation is as high, if not higher, than the optimum required 

 for growth in this sex. 



From the standpoint of lactation performance, fat has long been known 

 to stimulate this function, as demonstrated by Maynard and McCayj^"^ 

 McCay and Maynard, ^''^ and Maynard and Rasmussen.^"^ Loosli et al.-'^^ 



203 H. M. Evans, S. Lepkovsky, and E. A. Murphy, /. Biol. Chem., 106, 445-450 

 (1934). 



204 H. J. Deuel, Jr., C. R. Martin, and R. B. Alfin-Slater, J. Nutrition, 5^, 193-199 

 (1954). 



2»*L. A. Maynard and C. M. McCay, J . Nutrition, 2, 67-81 (1929). 



208 C. M. McCay and L. A. Maynard, J. Biol. Chem., 92, 273-280 (1931). 



207 L. A. Maynard and E. Rasmussen, /. Nutrition, 23, 385-398 (1942). 



208 J. K. Loosli, J. F. Lingenfelter, J. W. Thomas, and L. A. Maynard, J. Nutrition, 28, 

 81-88(1944). 



