146 



tlie origin of spasmophilic pheiioinenu consequent on decrease of 

 (lie ('oncenlriilion Ca-ions of the blood '). This concentration of depends 

 upon Ca-ions (he NailCX), and on the H-ion concentration. 



As for the influence of the concentration of the Ca-ions »i|)oii the 

 permeability' of the glomerular epithelium, it is so great that, even 

 when a potdssiuui-free liquid is sent through the kidney, I'etention 

 of the physiological quantity of glucose was still observable"). 



This being the fact, it seemed interesting to us to investigate inith 

 what liquid the vascular system of the froi} had to be perfused 

 in order to prevent the production of (edema in the hindlimb. 



We were all the more induced to inquire into this matter, since 

 some years back Gunzbukg ') occupied himself with (his question in 

 the Utrecht Physiological Laboratory. He found that, when perfusing 

 the vascular system of the frog with a fluid such as Ringer had 

 used for the heart, and which differed from ours in NaHCOg 0.02 "/o 

 being used instead of 0,2 7,-0,285 7„, KCI 0,01 7„ was indispens- 

 able to prevent oedema. So, in Gunzburg's experiments oedema 

 arose when the fluid was potassium-free or when too large an 

 amount of K was present. Instead of K he coidd use also Uranium, 

 Thorium or Rubidium in definite quantities. It is evident, therefore, 

 that, according to Gunzburg, K is indis|)ensable in this case, and 

 this indispensabilify is, according to him, due to the specifically 

 radio-active effect of this element. 



But Gunzburg also delected that in Ringkr's mixture K could be 

 left out, when the mixture was saturated with oxygen, in which 

 case (Kdema was also prevented. We shall revert to this point. 



It has been stated that in the circulating fluid Hamburger and 

 Brinkman could do entirely without K. In that case, however, the 

 Ca-ion concentration should have a definite value. The question 

 now arose : can wdema he prevented in the frog's limb inith a. 

 potassium-free circulating fluid, the Ca-ions concentration being ac- 

 curately fixed ? 



In order to find an answer to this question we have a series of 

 experiments which yielded unexpected results with refeience to the 

 influence of the Ca-ions concentration on the lumen of the blood- 

 vessels (capillaries). 



Of course the inquiry was begun by repeating Gunzburg's experi- 

 ments. A perfusion of the ordinary Ringer's liquid (NaHCO, 0,027J 



') Van Paassen, Ned. Tijdschr. v. Geneesk. 65, 2e helft, nr. 17, 1921. 

 ') Hamburger and Brinkman, These Proceedings Vol. XX, p. 668; Biochem. 

 Zeilschr. 88, 97, 1918. 



8) Gunzburg, Arch. Néerl. d. Physiol. 2, 364, 1918. 



