THE PITUITARY BODY 



prolan could be demonstrated in the placenta particularly in 

 the early months when the urinary excretion was highest. 

 Confirmatory studies were made by Murata and Adachi 

 (1927), Klein (1929), and Bourg, Collip, Motta, Philipp, and 

 Wiesner in 1930. No accurate quantitative studies of the 

 amount of prolan in the placenta as compared with other 

 tissues during pregnancy have been made. However, there 

 appears to be no other tissue in pregnant women, including 

 the anterior pituitary, as rich in gonad-stimulating prin- 

 ciple(s). Moreover, prolan is no longer excreted after the re- 

 moval of all the placenta, but it may still be excreted if living 

 remnants of the placenta, as in cases of abortion, are not com- 

 pletely removed (von Arvay, 1934). As will be shown in dis- 

 cussion later, women with tumors of placental origin (hy- 

 datidiform mole, chorionepithehoma) often excrete tremen- 

 dous amounts of "prolan" in the urine. Such tumor tissue, 

 including metastases, contains "prolan." Finally, an argu- 

 ment by analogy may be offered: the placenta secretes 

 oestrin during pregnancy and may therefore secrete prolan. 

 The other most probable origin of the prolan of pregnancy 

 appears to be the anterior pituitary, because prolan seems to 

 produce gonad-stimulating effects like those of implants or 

 extracts of the anterior pituitary. However, the more the 

 two are compared, the less alike they appear. A strong argu- 

 ment against the pituitary origin of prolan was furnished by 

 Philipp (1930), who found that little or no gonad-stimulation 

 could be produced by implants of the anterior pituitary of 

 pregnant women in comparison with similar implants of men, 

 non-pregnant women, and women after delivery.^" This ob- 

 servation was confirmed by Zondek and others. However, 

 Zondek still maintained that prolan is of pituitary origin and 

 simply is stored in the placenta. He believed that hyper- 



''° Evans and Simpson (1929); Bacon (1930); Ehrhardt and Mayes (1930); 

 Zondek (1931); Magistris (1932); and Siegert (1933) have studied the gonadotropic 

 potency of the anterior pituitary of pregnant animals. 



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