148 



surprising, therefore, that the ratio of K- en Ca-ions is of great 

 importance for the periiieabilit}' of the vascuhir wall. It is evident 

 that in an NaCl-(!aCl, mixture the constricting power of J 3 mgr. 

 Oa-ions per Litre is so great, as to keep away oedema. In the 

 presence of more than 13 mgr. Ca-ions e.g. 20 mgrs, as is the case 

 in Gunzbukg's fluid, (jedeina will ensue, if not a certain amount of 

 K is added to counteract their effect. A similar phenomenon appealed 

 in the case of the kidneys viz. tliat an excess of Ca-ions content of 

 the ciicuiating fluid produced permeability of the glomerular epithe- 

 lium for glucose '). The same thing was found by Brinkman ') with 

 regard to the red blood corpuscles. Likewise Nkuschlosz ') physico- 

 chemical expei-iments demonstrated that the surface-tension of a 

 lecithin-suspension in NaCl is as well influenced in the same manner 

 by too little as by too much Ca. 



We now tried to ascertain, whether oedema would arise when 

 using a mixture of NaCl — CaClj which contained much more than 

 0,007 7„ of CaCl,. 6 aq., just as had occurred when the amount 

 was 0,006 7.. 



With a view to this 0.01 '/, CaCl, 6 aq. (instead of 0,007 "/J was 

 dissolved in NaCl 0.6 7o- We expected oedema to come forth. It did 

 not come forth, though, which was owing to a quite unexpected 

 phenomenon : the perfusion of the liquid through the vessels stopped 

 abruptly. It could not be restored even through a considerable rise 

 of the hydrostatic pressure. When the same result was obtained 

 several times running, also with higher Ca-ions concentrations *), 

 further experiments concerning the influence of a higher Ca-ions 

 concentration on the producing of oedema had to be relinquished, 

 and vascular contraction was supposed to come into play. 



Now the assumption was warrantable that the vascular contraction 

 (spasm, tonus) would disappear on addition of K. It appeared, indeed 

 th<tt when to the circulating Jiuid {NaCl 0,6° / ^^ -f- CaCl^ . 6 aq. 0.01 7o) 

 0.01 7o t^^l '^^^^ added the per fusion of the liquid was restored again. 



We are justified in concluding from this that when, in a system 

 Na -|- Ca, the Ca-ions concentration is higher than agrees with CaCl, . 

 6 aq. 0.007 7o» ^ constricting influence is exercised on the vessels, 

 which may be counteracted by K-ions. This action seems to be 

 reversible; it may be repeated several times. 



'•) Hamburger u. Brinkman, Biochem. Zeitschr, 95, 101, 1919. 



2) R. Brinkman, Broch. Zeitschr. 95, 101 (1919), 



3) Neuschlosz, Pllüger's Archiv f. d. ges. Physiol. 181, 17, 1920. 

 *) More about this in a subsequent publication. 



