3866
The aim of this study was to investigate the effects of caffeine ( 20 mg / L ) intake on cadmium ( 15 mg / L ) accumulation in the rat blood , testes , epididymis and prostate as well as cadmium - induced changes to the antioxidant defense system of the epididymis .
 caffeine, cadmium, cadmium
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 caffeine, cadmium, cadmium