EFFECTS OF EXTRACTS OF PARS NEURALIS 



to man is followed by a diminution in the concentration of cal- 

 cium in the blood. The concentration of calcium in the blood 

 of the toad, Xenopiis laevis, is lower 3 hours after the injection 

 of 0.5-1.0 cc. of posterior-lobe extract into the dorsal lymph 

 sac (Shapiro and Zwarenstein, 1934). In the thyropara- 

 thyroidectomized dog the administration of a posterior-lobe 

 extract is not followed by any change in the concentration 

 of the blood-calcium (Larson and Fisher, 1928). Toxopeus 

 (1930) believed that in dogs, to which bromide had been 

 administered, the striated muscle contained more bromide 

 and the skin contained less promide after the administration 

 of a posterior-lobe extract; the reverse was thought to occur 

 in thyroidectomized or thyroid-fed animals which received 

 no posterior-lobe extract. According to Mclntyre and van 

 Dyke (1931), the distribution ratio of chloride and/or bro- 

 mide between erythrocytes and serum (dog) is not aifected 

 by the administration of posterior-lobe extract." 



The injection of posterior-lobe extract into a lymph sac of 

 the frog or toad kept in water causes an increase in the body- 

 weight (e.g., a gain of 20 per cent in weight 5-10 hours after 

 the injection of 5-10 units of extract). Brunn (1921), who 

 first studied this effect, concluded that the increased water 

 content of the frog's body is not due to a renal effect ana- 

 logous to diuresis inhibition in mammals. The effect was also 

 observed after nephrectomy. From the studies of Brunn and 

 others (Biasotti, 1923; Jungmann and Bernhardt, 1923; 

 Heller, 1930; Steggerda, 1931; Novelli, 1933; Steggerda and 

 Freedman, 1933; Steggerda and Essex, 1934),'-' it may be 

 concluded that: (i) the effect appears to be due to a change 

 in the physiology of the skin and (2) the oxytocic principle 

 has a considerablv greater effect than the vasopressor prin- 

 ciple. The increase in the body-weight due to the extract is 

 greater in summer than in winter; also it is less in the de- 



'3 See also Daniloff (1934), and Dietel and Ditsch (1934). 



^'^ Collin and Drouet (1932) doubted that the effect could be produced. 



[359I 



