I guess that counter regulatory hormones in our context are ones that oppose the action of insulin -- make your blood sugars go up.  These include adrenaline (epinephrine and norepinephrine), cortisol, growth hormone, glucagon...
 
Nikki mentioned Somogyi effect (I think I remember it as rebound effect) and here is some discussion on it:
 
http://www.emedicine.com/med/topic2098.htm
 
Childrenwithdiabetes.org has this helpful layman's definition:
 
Counterregulatory