None of the effects I mention require intra-cellular action. The "signals" mentioned are sent from one cell or cells to other cells. AT3s action would occur extra-cellular. Hope that clears it up for you.
Incidentally there is no prohibition to protiens entering and operating intra-cellular. This is what cytochines do...they are protiens which are produced and secreted by one cell and enter another cell to effect its behavior.
Market Data 
Markets 
AI
