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 [1]
 
Childrenwithdiabetes.org has this helpful layman's definition:
 
Counterregulatory
An attempt by the body to correct a perceived abnormality. The correction may be in the form of an endocrine, neuronal, or other mechanism. In diabetes, this is a term that is usually used to describe the body's normal response through other hormones, epinephrine and glucocorticoids (which are called "counterregulatory hormones") to correct blood sugars that are too low.