THE PITUITARY BODY 



hormones are causally related to the symptoms.'^ Van 

 Bogaert (1936) was convinced that neither the pituitary nor 

 the adrenals is etiologically important in hypertension but 

 that the pituitary may be important in maintaining the 

 symptoms. 



The relationship between the pituitary and the experi- 

 mental hypertension due to renal ischemia produced by the 

 clampof Goldblatt and others has been investigated in the dog 

 by Page and Sweet (1936-37). In normal animals hypophy- 

 sectomy caused some reduction of the arterial blood pres- 

 sure. In dogs in which hypertension (240/160 mm. Hg) had 

 been produced by means of Goldblatt's clamp, the high level 

 of arterial pressure was maintained for several months unless 

 hypophysectomy was performed. Some weeks after hypophy- 

 sectomy, the blood pressure fell, sometimes nearly to 

 normal (150/100 mm. Hg), sometimes below normal (90/40 

 mm. Hg). Subsequent further constriction of the renal arter- 

 ies again produced a rise in blood pressure which tended to 

 be transient. The administration of thyroid extract also 

 might be followed by a moderate increase in arterial pressure 

 (see Fig. 28). The authors concluded that the effects of 

 hypophysectomy were indirect and depended probably upon 

 the removal of the pars glandularis without which the thyroid 

 and adrenal glands performed their functions imperfectly. 

 It is regrettable that this interpretation was not strengthened 

 by observing the effects of extirpation of either the pars 

 glandularis or the pars neuralis alone, because their observa- 

 tions do not satisfactorily exclude the possibility that the 

 pars neuralis plays some part in maintaining the hyperten- 

 sion. Page (1936) was not able to detect any increased 

 amount of hypertensive principle in the blood of dogs with 

 the hypertension of renal ischemia; however, his method of 



'•! Positive results were obtained in 20 of 28 patients with essential hypertension 

 and in 6 with Cushlng's syndrome. The findings were negative in 8 patients with 

 eclampsia or renal disease of pregnancy. 



[288 1 



