15905
Significantly , the venom exhibited inhibitory effects on TTX - R Na ( + ) and T - type Ca ( 2 + ) currents , suggesting that there exist both channel antagonists which might be valuable tools for investigation of both channels and drug development .
 Chemical: Na ( + ); Chemical: Ca ( 2 + )
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: Na ( + ), Ca ( 2 + ) 
Answer:
 Chemical: Na ( + ); Chemical: Ca ( 2 + )