INHIBITORY EFFECT OF TNP-470, A NEW ANTI-ANGIOGENIC AGENT, ON THE ESTROGEN-INDUCED RAT PITUITARY-TUMORS

An agiogenic inhibitor, TNP-470, is an analogue of fumagillin. This st udy reports the effects of TNP-470 and bromocriptine on the normal pit uitary glands and estrogeninduced rat pituitary tumors. TNP-470 inhibi ted the increase of normal pituitary weight and the tumorigenesis indu ced by estrogen. The decreased labelling index in the pituitary cells, showed that TNP-470 may suppress the activity of cell proliferation a s the result of anti-angiogenesis. Combination treatment with TNP-470 and bromocriptine was much more effective than TNP alone. These result s suggest that TNP-470 is a potentially beneficial drug for pituitary tumors.