90 



The Endocrine Organs 



coid of the pituitary is comparable to that of those drugs which act as 

 specific diuretics upon the secreting cells of the kidney, as distinguished 



from those which pro- 

 duce diuresis by increas- 

 ing the water content 

 of the blood or by merely 

 increasing the general 

 blood-pressure. 

 . | The diuretic action 



2 I of the pituitary autacoid 

 | -« is not antagonised by 



3 I atropine. This may be 

 | . taken as a sign that 

 § I it does not act through 

 | | nerves or nerve-endings, 

 |* | but directly upon the 

 I | kidney cells ; in this re- 

 s ^ spect also it resembles 



- ■ the action of secretine 

 S "3 



- I upon the pancreas. 



Effect on Secretion of 



* § Cerebrospinal Fluid. — 

 3 | It has been shown by 

 a | Weed and Cushing that 

 3 a extracts of posterior lobe 

 | * also contain an autacoid 

 m ■' which stimulates the 

 = « flow of cerebro - spinal 

 S | fluid (fig. 63). This is 

 5 « not dependent on in- 

 q 2 crease of blood-pressure, 

 Jj I for it may be accom- 



* r panied by a fall instead 

 » | of a rise of pressure, and 



« by an increase in depth of 

 the respirations : the in- 

 creased flow of cerebro- 

 spinal fluid seems to 

 be independent of these 

 circumstances. 



Effect on Milk Secre- 

 tion. — It was found by Ott and Scott that in the goat an injection of 

 pituitary extract into a vein greatly increases the quantity of milk which 

 can be drawn from the udder in a given time after the injection, as com- 

 pared with that which could be obtained in a similar period immediately 



