INFLUENCE OF HELODERMA VENOM. 109 



experiment is considerably larger than the lethal dose. Yet none of the ani- 

 mals succumbed to the injection! It appears, therefore, that the venom is 

 either very rapidly destroyed within the bodies of the animals or prevented 

 from combining with the central nervous system, either as a result of being very 

 rapidly eliminated from the body or in some other way. It seems most prob- 

 able that the failure of the venom to cause death under these conditions is not 

 due to the destruction but perhaps to the elimination of the venom, since in the 

 normal uninfused animals the same possibilities for the breaking-down of the 

 venom exist, whereas the possibilities for the elimination of the venom are not 

 so good as in the infused rabbits. 



These experiments make it highly probable that the venom acts only indi- 

 rectly on the diuresis by influencing the general arterial blood-pressure and 

 that it does not exert a direct influence on renal cells or vessels. With the fall 

 of blood-pressure the secretion of urine diminishes, while with the increasing- 

 pressure the secretion of urine also increases. 



EXPERIMENTS WITH NEPHRECTOMIZED RABBITS. 



In further experiments we infused venom-sodium-chloride solution into* 

 rabbits whose kidneys had previously been removed. Under such conditions 

 all the infused fluid was retained within the body of the animal, and we were 

 able to determine more exactly the influence of the addition of venom to the 

 sodium-chloride solution on the production of peritoneal transudate and intes- 

 tinal fluid. We carried out seven experiments. In one 600, in four 700, and in 

 two 800 c.c. were infused. In all these experiments 20 mg. of venom had been 

 added to 800 c.c. of sodium-chloride solution. An average of 104 c.c. of peri- 

 toneal transudate was produced for every 1,000 c.c. of fluid infused. In con- 

 trol experiments, carried out some time ago,* and in which pure sodium-chloride 

 solution was infused into rabbits, 109 c.c. of peritoneal transudate were pro- 

 duced for every 1,000 c.c. of fluid infused. The addition of venom to the 

 sodium-chloride solution has, therefore, little or no effect on the production of 

 peritoneal transudate. 



Before the infusion was started, and at the time the kidneys were removed, 

 the small intestines were clamped at both the upper and lower ends, and at the 

 conclusion of the experiment the fluid contained in them was measured in each 

 case. An average of 130 c.c. of fluid was found in the intestines for every 

 1,000 c.c. of fluid infused. In previous experiments in which sodium-chloride 

 solution alone was infused,* we had found an average of 94 c.c. of fluid was col- 

 lected from the intestines for every 1,000 c.c. infused. Thus the addition of 

 venom to the infused fluid had increased the transudation of fluid into the 

 intestines, a finding in agreement with the results of similar experiments in 

 non-nephrectomized animals and also with the autopsy findings of animals that 

 had died after a single injection of venom. 



*F!eishcr, Hoyt and Loeb, Jour. Exper. Med., 1909, xi, 291. 



