1504
We conclude that the beta - adrenergic agonist , isoproterenol , has little influence on vascular capacitance or liver volume of dogs , unless the hepatic outflow resistance is elevated by agents such as histamine .
 None
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 None