MINERAL METABOLISM 337 



svmptoms of tetany, injection of neutral or alkaline salts of ^N"a or K 

 intensifies them. 



By intravenous injection of phosphoric acid and its Xa salts Binger 

 lias been able to reduce the Ca of the serum from 10 mg. to 6 mg. per 

 lv>0 c.c. Tetany results at this point unless the pll is above 6; if the 

 solution injected has a pll greater than this no tetany results. A similar 

 marked reduction of blood Ca to as low as 1.5 mg. per 100 c.c. without 

 tetany occurs in nephritis where the blood is extremely high in acid 

 phosphates. Parathyroidectomy is accompanied by an increase in the 

 acid phosphates of the blood and during a tetanic seizure the ammonia of 

 the blood is about twice normal, while injection of ammonium carbonate 

 into normal animals will bring on symptoms of tetany immediately (Green- 

 vald(a)(6); Watanabc(c) ; Jacobson). That the hydrogen ion con- 

 centration is a determining factor is clear from the work of Binger and of 

 Marriott and Howland, and from recent work which showed increased 

 alkalinity of the blood following parathyroideetomy and just before con- 

 vulsions began (Wilson, Stearns and Thurlow) ; also from the coincidence 

 of tetany and increased alkalinity of the blood as a result of intravenous 

 infusion of NaIICO ;j (Harrop(a) ), and of operations on the stomach 

 which exclude the acid secretion from the duodenum (McCann). On 

 the other hand, blood which has been dialyzed against a solution contain- 

 ing everything normal to blood except calcium when transfused into the 

 isolated leg of a dog resulted in over-stimulation of the nerves (MacCallum, 

 Lambert and \ r ogel). 



There is some difference of opinion regarding the blood Ca in infantile 

 tetany, Longo (quoted by Howland and Marriott), finding a normal con- 

 tent in eight cases while others have found it much reduced (ISTeurath; 

 Brown, MacLachlan and Simpson), and Rowland and Marriott say "con- 

 vulsions may be expected when the Ca of the serum becomes less than 7 

 mg. per 100 c.c." They find the Mg and inorganic phosphates of the 

 blood remain normal. Calcium absorption is little if at all affected in in- 

 fantile tetany (Schwarz and Bass) and while the Ca content of nervous 

 tissue has been found (post mortem) below normal (Quest; Weigert(fc)) 

 it is not invariably so; but in cases where the Ca is normal the $~a and 



K are abnormally high, and the ratio n . ,. is high(Aschenheim(a)). 



-- 



A metabolism study of a baby having rickets and tetany (Fletcher) 

 has brought out a similar relation in the retention of these elements; while 

 the disease was in active progress the retention of CaO was 0.39 gr. daily 



"V -1_ T*" 



and the ratio = 1.5, during the later period during which there 



was marked improvement, in the symptoms the retention of CaO was 0.44 



"NT" I T^ 



<rr. daily, and the ratio . * = 0,72. Howland and Marriott 



Ca -f Mg 



