THE PITUITARY BODY 



that the prolonged injection of gonadotropic extracts is fol- 

 lowed by the production, at some unknown site, of "antihor- 

 mone" which can be detected in the serum, numerous au- 

 thors have made many further investigations of the phe- 

 nomenon. The production of antihormone is of practical im- 

 portance; for, if an injected extract produces antihormone, 

 successful therapy may be thwarted and the patient's condi- 

 tion even may be worsened.''' The other important question 

 is the significance of possible antihormone balance to gonado- 

 tropic and other hormones secreted by the gland in situ. 

 Chiefly from experiments in parabiotic animals there is good 

 evidence against the view that the body may produce its own 

 antihormone to inhibit excessive secretion by a gland like the 

 anterior pituitary. Also the evidence from artificially intro- 

 duced hormone is by no means concordantly in favor of the 

 antihormone hypothesis. 



Usually the prolonged injection of a gonadotropic extract 

 is followed by progressively less efi'ect, until finally the ovaries 

 or testes of the injected animals may actually be smaller than 

 those of animals not receiving treatment. xAntihormone can 

 then be readily detected in the serum by its inhibitory eff"ect 

 on the gonadotropic action of the extract when the serum and 

 extract are injected into fresh animals. An attempt again to 

 stimulate the gonads of the animals receiving the prolonged 

 injections after a period of rest either fails or produces only a 

 slight change. Most investigators are in agreement with 

 these general statements. However, the interpretation of the 

 phenomenon is a matter of disagreement which perhaps can- 

 not be settled from a consideration of the published data. 



One obvious basis for the development of antihormone in 

 response to the long-continued injection of gonadotropic ex- 



"' Spence, Scowen. and Rowlands (1938) concluded that the injection into human 

 beings of prolan (1,000 rat-units weekly) or extract of the pig pituitary (30-50 R.U. 

 weekly) for varying periods up to 7 months was followed by the appearance of no 

 "serious amount of iinti-gonadotropic activity" in the serum. 



Rowlands and Parkes (1937) suggested that antihormone obtained from serum 

 of suitably injected animals might be used to lessen the effects of hormones secreted 

 by the hyperactive pituitary. 



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