Hi Lily:

This is an interesting site with definitions:

http://www.nhlcyberfamily.org/blood.htm

Blood Urea Nitrogen (BUN) is waste from the liver, processed by the kidneys. It also reflects whole carbohydrate storage, liberation, and continuation in the liver associated with many glands (i.e., kidneys). BUN tends to rise in dehydration and in kidney or heart failure. Prednisone and other steroids may cause BUN to rise. Increases in BUN can also indicate liver and/or thyroid inactivity. Decreased BUN indicates pancreas and/or adrenal inactivity. BUN can also be elevated by a high protein diet or recent exercise.

This one for the a/g ratio:
http://www.labtestsonline.org/unders...s/tp/test.html

Hope these help,
Kat