ANATOMY OF THE PITUITARY BODY 



pressor hormones (including the diuretic-antidiuretic hor- 

 mone) of the pars neurahs is uncertain; unquestionably the 

 highest concentration of these hormones is found in the pars 

 neuralis. General statements cannot be made with respect to 

 a presumed division of function among different cell types, 

 such as those of the pars glandularis. In a giv^en animal, how- 

 ever, there may be some correlation between histological 

 change and the amount of a hormone. 



The oxyphilic cells are thought to secrete the growth-pro- 

 moting hormone because (i) the symptoms of the most clear- 

 cut disease of the pituitary in man, acromegaly, are apparent- 

 ly due to an excessive secretion of the growth-promoting 

 hormone by the oxyphilic cells of a tumor (adenoma) and 

 (2) growth-promoting effects may be produced by ox pitui- 

 tary tissue composed of oxyphils and reserve cells, but not by 

 tissue composed of basophils and reserve cells (Smith and 

 Smith, 1923). If we are to accept other evidence, however, 

 the oxyphilic cells also appear to be responsible for the secre- 

 tion of a gonad-stimulating hormone in man (Philipp, 1930; 

 Kraus, 1932-33) and in the pig. According to Nelson (1930), 

 the pituitary of the fetal pig is characterized by a marked 

 differentiation of the oxyphils only when the crown-rump 

 length is 16-17 cm. The chromophils are predominantly oxy- 

 philic at a fetal length of 20 cm., when Smith and Dortzbach 

 (1929) detected gonadotropic hormone. In the younger fetus 

 (about 10 cm.), the chromophils are chiefly basophilic; pitui- 

 tary implants then cause growth in hypophysectomized rats 

 but no gonadotropic effect in immature mice. 



The data just cited suggest that the basophils in the pig 

 secrete the growth-promoting hormone. More generally held 

 is the view that the basophils specifically elaborate the gonad- 

 otropic hormone(s). In the woodchuck, the period of great 

 sexual activity after hibernation appears to be correlated 

 with a marked increase in the number of basophils in the pars 

 glandularis. In the rat and rabbit, castration or spaying is 



[29] 



