Mn (III) hematoporphyrin. A potential MR contrast agent.
Manganese (III) hematoporphyrin (MnHP), a new and stable complex, was prepared, and its toxicity and magnetic resonance (MR) imaging properties were evaluated. In tests of acute and subacute toxicity, no deaths resulted from bolus intravenous injections of 13 or 19 mumols/kg of MnHP, but there was a 33% mortality when the dose was 38 mumols/kg. Laboratory results were normal in the surviving rats. Ultraviolet- visible spectroscopy of the urine and serum of two rats injected 24 hours previously with 38 mumols/kg MnHP revealed no free HP, suggesting in vivo stability of MnHP. Finally, using a standardized imaging protocol, there was a mean increase of 37% in the liver-to-muscle intensity ratios in four rats injected 24 hours previously with 25 mumols/kg MnHP when compared to paired controls (P less than .005). In addition, obvious visual increase in the signal intensity of the liver on T1-weighted images was seen in animals tested with 13 and 19 mumols/kg of MnHP. The results suggest that further evaluation of MnHP as an MR contrast agent for the liver is warranted.
Bohdiewicz
P J
PJ
Department of Radiology, Columbia-Presbyterian Medical Center, New York, NY 10032.
Lavallee
D K
DK
Fawwaz
R A
RA
Newhouse
J H
JH
Oluwole
S F
SF
Alderson
P O
PO
D000818:Animals; D003287:Contrast Media / Q000138:chemical synthesis* / Q000633:toxicity; D006415:Hematoporphyrins / Q000138:chemical synthesis* / Q000633:toxicity; D008099:Liver / Q000033:anatomy & histology; D008279:Magnetic Resonance Imaging; D008297:Male; D008345:Manganese; D008665:Metalloporphyrins / Q000138:chemical synthesis* / Q000633:toxicity; D051381:Rats; D011917:Rats, Inbred Lew
D003287:Contrast Media; D006415:Hematoporphyrins; D008665:Metalloporphyrins; D008345:Manganese; C065506:manganese (III) hematoporphyrin