INFLUENCE OF HELODERMA VENOM. 107 



elusion of the experiment. The addition of small quantities of adrenalin 

 causes, therefore, a slight rise in the blood-pressure, and prevents, or at least 

 delays, to some extent, the usual fall after 500 or 600 c.c. of venom-sodium- 

 chloride solution has been infused (see figs. 20 and 21). 



In the experiments in which the 1 to 600,000 adrenalin solution was used 

 the diuresis increased quite markedly after the infusion of the adrenalin, and 

 the secretion of urine reaches a relatively high level, when compared with the 

 secretion at a similar period, during the infusion of the venom-sodium-chloride 

 solution. This was true in two of the experiments at least. In one experiment 

 no decrease either of diuresis or blood-pressure was observed in the late stages 

 of the infusion, whereas in the other experiment a slight decrease in the secre- 

 tion of urine is noted simultaneously with a slight fall in the blood-pressure. 



In a third experiment,* in which we infused a 1 to 100,000 adrenalin solu- 

 tion during the second period of the experiment, the rise of blood-pressure fol- 

 lowing the infusion of the adrenalin solution was more pronounced than in the 

 other two, and at the same time the secretion of urine was very markedly 

 increased after addition of the adrenalin (see fig. 24). 



From these experiments we may conclude that adrenalin counteracts to a 

 small extent the blood-pressure lowering action of the venom. In view of the 

 fact that in one experiment the blood-pressure began again to fall even after 

 the addition of adrenalin, it is probable that this influence of adrenalin would 

 eventually be overcome by the depressing action of the venom. We further 

 note that simultaneously with the rise of blood-pressure following the addition 

 of adrenalin, the diuresis is also increased; it is therefore probable that the 

 diminution of diuresis resulting from the addition of venom to the infused fluid 

 is due not to a specific action of the venom on the kidneys, but to the lowering 

 of the arterial pressure. 



The average amount of urine secreted per 1,000 c.c. infused was greater in 

 the experiments in which adrenalin was added to the venom-sodium-chloride 

 than in the experiments in which venom-sodium-chloride solutions alone were 

 infused. In these experiments, as well as in the former experiments w T ith 

 venom but without the addition of adrenalin, the quantity of intestinal fluid 

 was increased, while the ascitic fluid was absent. 



TABLE 3. Non-nephrectomized rabbits infused with venom-sodium-chloride solutions to which 



adrenalin was added. 



*In this experiment a large quantity of venom was injected intravenously some time after the infusion of adre- 

 nalin was started, but at a time when the influence of the addition of adrenalin had been clearly demonstrated. 



