THE PITUITARY BODY 



rabbits, do not cause the production of substances behaving 

 like antihormone toward gonadotropic extracts of sheep or 

 human pituitary. Several recent authors concluded that vari- 

 ous gonadotropic extracts from the pituitary, blood, or urine 

 of different animals could produce antihormone which is not 

 species specific (Gregerson, Clark, and Kurzrok; Parkes and 

 Rowlands, 1936; Collip, Rowlands, Thompson and Gushing, 

 1937). These experiments are the most complete and exten- 

 sive. However, mixed results may be obtained, so that some 

 extracts produce antihormone which appears to be partially 

 or completely species characteristic (Collip, Rowlands, 1937). 

 Finally, several observers found, at least with their prepara- 

 tions, that antihormones toward gonadotropic extracts in- 

 hibit the effect only of extracts of tissue or urine of the animal 

 of the same species (Fluhmann, 1935; Gustus, Meyer, and 

 Dingle, 1935; Brandt and Goldhammer, 1936). As far as 

 pituitary gonadotropic extracts are concerned, the weight 

 of evidence appears to be against the view that antihormone 

 is species specific. Perhaps there is true "species specificity" 

 when extract of human pregnancy-urine (prolan) or preg- 

 nant-mare serum is used as an "antigen" (Rowlands). 

 "Source specificity" is believed by Rowlands (1938) to be 

 complete in the case of pregnant-mare serum, although others 

 (e.g., Thompson and Cushing) have obtained different re- 

 sults. It is probable that, if antihormone formation is analo- 

 gous in some phase or phases to the formation of immune 

 bodies, the problem is rendered more complex and more diffi- 

 cult to interpret than most immune reactions, because of the 

 possibility that the hormone "antigens" are more complex 

 than is usually suspected (see Rowlands, 1938).''' The con- 



'■ The method of detecting antihormone (cf. failure of ovarian hypertrophy in 

 the rat and failure of ovulation in rabbit) may determine whether the result is posi- 

 tive or negative. Using an extract of the anterior pituitary of the ox as "antigen," 

 Rowlands (1937-38) found that its antihormone antagonized the gonadotropic 

 action of sheep pituitary extract (ovarian hypertrophy in rats), whereas Parkes 

 and Rowlands (1936) found this not to be the case when they used the production 



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