{HEAD ~ Drugs} that upregulate the concentration of {TAIL ~ cAMP} in cells are well known 
{ HEAD ~ Drugs } that upregulate the concentration of { TAIL ~ cAMP } in cells are well known
HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH